BR0014255B1 - component for use in printing system. - Google Patents

Description

"COMPONENT FOR USE IN PRINTING SYSTEM"

Field of the Invention

This invention relates to inkjet printers. In particular, this invention relates to novel designs and methods of manufacturing inkjet printheads capable of providing ink droplet tail detachment control and preventing overrun of the meniscus so as to overcome the problems of puddle formation, feather targeting, and wrinkling associated with thermal inkjet printing.

Invention History

The present invention relates generally to printhead structures for use in providing ink to a substrate and more particularly to a new orifice plate designed for attachment to a printhead. The orifice plate includes a number of important structural aspects that enable high levels of print quality to be maintained over the life of the printhead.

Substantial developments have been made in the field of electronic printing technology. Today, there is a wide range of highly efficient printing systems that are able to deliver ink quickly and accurately. Thermal inkjet systems are particularly important at this point. Printing units using thermal inkjet technology basically involve an apparatus that includes at least one ink reservoir chamber in fluid communication with a substrate (preferably made of silicon [Si] and / or other comparable materials. ) having a plurality of thin film heating resistors. The substrate and resistors are held within a structure that is conventionally characterized as a "printhead". Selective activation of the resistors causes thermal excitation of the ink materials stored within the reservoir chamber and their expulsion from the printhead. Representative thermal inkjet systems are discussed in U.S. Pat. 4,500,895 to Buck et al; 4,771,295, Baker et al .; 5,278,584 to Keefe et al; and in the "Hewlett-Packard Journal", Vol. 39, No. 4 (August, 1988), all incorporated herein by reference.

The ink supply systems described above (and comparable print units using thermal inkjet and other ink ejection technologies) typically include an ink containment unit (e.g., a housing, vessel or tank) having a self-contained ink supply within to form an ink cartridge. In a standard ink cartridge, the ink containment unit is attached directly to the remaining cartridge components to produce an integral and unitary structure in which the ink supply is considered to be "onboard" as shown, for example, in the ink cartridge. US patent no. 4,771,295, by Baker et al. However, in other cases, the ink containment unit is provided at a remote position within the printer, with the ink containment unit operatively connected to and in fluid communication with the printhead using one or more ink transfer ducts. . These specific systems are conventionally known as "off-center" printing units. Non-limiting and representative off-center ink delivery systems are discussed in the patent pending patent application, U.S. 08 / 869,446 (filed 06/06/97) entitled "AN INK CONTAINMENT SYSTEM INCLUDING PLURAL-WALLED BAG FORMED OF INNER AND OUTER FILM LAYERS" (Olsen and others) and in the patent pending application, having holders US no. 08 / 873,612 (filed June 11, 1997) entitled "REGULATOR FOR A FREE-INK INKJET PEN" (Haulk et al.), Which are incorporated herein by reference. The present invention (as discussed below) is applied to both onboard and off-center systems, which will be readily apparent from the discussion provided herein.

In order to effectively deliver ink materials to a selected substrate, thermal inkjet printheads typically include an outer plate member, known as a "nozzle plate" or "orifice plate", which includes a plurality of ink eject holes (for example, openings or holes) through it. Initially, these orifice plates were made from one or more metallic compositions, including, but not limited to, gold plated or palladium plated nickel and other similar materials.

However, recent developments in thermal inkjet printhead design have also resulted in the production of orifice plates that are produced from a variety of different organic polymers (eg plastics), including but not limited to film products. , consisting of polytetrafluoroethylene (eg Teflon®), polyimide, polymethyl methacrylate, polycarbonate, polyester, polyamide, polyethylene teraphthalate and mixtures thereof. A representative (e.g., polyimide based) polymer composition which is suitable for this purpose is a commercial product sold under the trademark "KAPTON" of E.I. du Pont de Nemours & Company of Wilmington, DE (USA). Orifice plate structures produced from the non-metallic compositions described above are typically uniform in thickness and highly flexible. They also provide numerous benefits, from reduced production costs to substantial simplification of the entire printhead structure, which translates into increased reliability, economy and ease of manufacture.

The manufacture of polymeric / plastic film type orifice plates and the corresponding production of their entire printhead structure is typically accomplished using conventional tape automated bonding (TAB) technology such as generally discussed in US patent no. 4,944,850 to Dion. Additional information regarding polymeric non-metallic orifice plates of the type described above is provided in the following U.S. Pat. 5,278,584 to Keefe et al. And 5,305,015 to Schantz et al. (Incorporated herein by reference).

Also of interest is the co-pending patent application having co-holders U.S. 08 / 921,678 (filed August 28, 1997) entitled "IMPROVED PRINTHEAD STRUCTURE AND METHOD FOR PRODUCING THE SAME" (Meyer et al.), Which is also incorporated herein by reference. In this document, a number of techniques are described for increasing the overall durability of polymeric film-type orifice plates. For example, in one embodiment, a backing is applied to the upper surface and / or the lower surface of the orifice plate.

Representative coatings include diamond-like carbon (which is also known as "DLC", "diamond-Iike carbon"), at least one metal layer (for example, chrome [Cr], nickel [Ni], palladium [Pd], gold [Au], titanium [Ti], aluminum [Al] and mixtures thereof), and / or a selected dielectric material (eg silicon nitride, silicon dioxide, boron nitride, silicon carbide and carbon silicon oxide ). This technique is designed to increase the overall abrasion and creep resistance of the thin film orifice plate structure and avoids "dimple" formation problems associated with these components. In addition, the overall durability of the completed structures is particularly increased through the use of DLC and the other compositions listed above.

However, other important factors must be considered in order to produce a printhead using a non-metallic orifice plate that is capable of producing clear, distinct and vivid printed images over extended periods of time. For example, a condition known as "wrinkles" or "wrinkles" may occur on printheads using thin-film polymeric (e.g., plastic) orifice plates of the type discussed herein. This condition can cause significant print quality deterioration if left unchecked. Conventionally designed thermal inkjet printers typically employ at least one wiper element (typically made of elastomeric rubber, plastic or other comparable materials) to keep the outer surface of the orifice plate clean and free of residual ink and other foreign matter, including paper fibers and the like. A representative cleaning system used for this purpose is described in U.S. patent no. 5,786,830 to Su et al., Which is incorporated herein by reference. Printheads that use thin-film organic polymer-based orifice plates are often adversely affected by the cleaning process. Specifically, passing the wiper element (s) over this type of orifice plate may cause the plate structure to "lift" along the edges of the holes, thus creating a puckered appearance, with structures similar to "wrinkles" being formed at the peripheral edges of each hole. This physical deformation of the orifice plate (and the resulting change in orifice geometry / planarity) can cause significant changes in the ink drop path, ie the desired path to be followed by the ink drop in order to create the final image. printed. These undesirable changes in orifice plate geometry prevent the ink droplet from traveling in its intended direction. Rather, the droplet is expelled inappropriately and is delivered to an unwanted location on the print media material (eg paper and / or other substrates). Deformation of the orifice plate as described above (including the creation of extraneous, "wrinkle" structures around the peripheral edges of the orifices) may also cause paint "puddle" to accumulate or form in these regions.

This can also change the ink drop trajectory by causing an unwanted interaction between the ink drop being expelled (particularly the end portion of each drop, or its "tail") with accumulated ink adjacent the holes. As a result, print quality degradation occurs over time.

These problems are again caused by two main factors, namely (1) the flexible, thin nature of the organic polymer orifice plates described herein; and (2) the physical forces imposed on orifice plates by conventional wiper structures (or other objects that may come into contact with the plates).

In summary, numerous adverse conditions are associated with "wrinkling" in a thin film organic polymer based orifice plate system, ranging from a noticeable deterioration in print quality to a reduced level of printhead longevity and increased maintenance needs. Prior to the completion of the present invention, there was therefore a need for a polymeric (e.g. plastic) orifice plate system that was highly resistant to the effects of repeated wiping using one or more ink wiping elements and which did not undergo ink path problems caused by "wrinkling" as previously described. The present invention is designed to accomplish these objectives in a highly effective and economical manner. In particular, the new orifice plate and printhead designs described here (which will be described in considerable depth below in the Detailed Description section of Preferred Configurations) provide the following important benefits: (1) a substantial increase in printhead / orifice plate longevity; (2) the ability to maintain precise control over ink drop trajectory over the life of the printhead; (3) claimed orifice plate compatibility with print units using a variety of different wiper systems that are used to clean the printhead; (4) the prevention of premature orifice plate damage, despite its thin film polymeric characteristics; and (5) the achievement of these objectives using a technique that avoids the deposition of additional material, layers and / or chemical compositions on the plate. which can increase the cost, complexity and overall manpower requirements associated with the printhead manufacturing process. Therefore, the present invention represents a considerable advance in printhead design technique and imaging technology.

Additional information regarding the claimed orifice plate and printhead structures (including specific data involving the technical aspects of the invention with preferred operating parameters and representative building materials) will be provided in the following sections of the Invention Summary and Detailed Description Preferred Settings. Likewise, the specific manner in which the claimed invention provides all the benefits described above will become apparent from the detailed information presented in these sections.

Accordingly, it is an object of the present invention to provide designs and methods of manufacturing inkjet printheads capable of controlling ink droplet tail detachment and preventing overrun of the meniscus so as to eliminate formation problems. pooling, feather targeting, and wrinkling associated with thermal inkjet printing.

It is an object of the present invention to provide an improved printhead for use in an ink supply system that is characterized by high levels of operational efficiency.

It is another object of the invention to provide an improved printhead that has a greater overall longevity compared to conventional systems.

It is another object of the invention to provide an improved printhead that uses a polymeric (e.g. plastic) orifice plate that is thin and flexible yet durable and resistant to deformation while applying physical force to it.

It is another object of the invention to provide an improved printhead using the new orifice plate described above, in which the orifice plate is especially resistant to the repeated cleaning effects of the ink cleaning elements that are normally used for cleaning purposes.

It is another object of the invention to provide an improved printhead that uses the new orifice plate described above, in which the orifice plate avoids the braking problems. "As stated previously," crimping "involves a break or" elevation "of the orifice plate around the peripheral edges of the nozzles caused by physical engagement of the plate with the aforementioned cleaning units (or other structures that engage the printhead during use.) This problem typically causes undesirable changes in the droplet path. ink leading to a deterioration in print quality.

It is a further object of the invention to provide an improved printhead using the new orifice plate described above that is generally characterized by improved operating efficiency, reduced maintenance problems, minimal system downtime and uniform print quality levels. over time.

It is a further object of the invention to provide an improved printhead using the new orifice plate described above that can be used with a wide variety of inkjet systems (including but not limited to those employing inkjet technology). thermal).

It is a further object of the invention to provide an improved printhead using the new orifice plate described above that can be used on many different printer units, including (1) self-contained "onboard" ink cartridges that have a supply internal ink associated with them; (2) "off-center" systems in which the printhead (and associated structures) are in operative connection / fluid communication with a remotely located ink supply.

It is a further object of the invention to provide an improved printhead that uses the new orifice plate described above, and in which the above benefits are achieved in a highly economical manner that is especially suited for mass production manufacturing processes.

It is a further object of the invention to provide an improved printhead using the new orifice plate described above and in which the above benefits are obtained without the application of layers of material or additional chemical compositions to the orifice plate.

Summary of the Invention

A new and highly efficient printhead structure will be described below, which provides numerous advantages over previous systems. As previously stated, the claimed printhead uses a specialized extended durability orifice plate, which avoids the problems associated with passing wiper units (or other structures) along the plate surface. The orifice plate is made of an organic polymer composition that is designed especially for this purpose. Earlier systems using thin film orifice plates derived from organic polymer were subject to a condition known as "wrinkles" or "wrinkles" that occurred during physical contact between the orifice plate surface and various objects, including wiper units. of ink and the like. This condition resulted in deformation of the orifice plate around the peripheral edges of the orifices (and / or adjacent regions), leading to the creation of wave-shaped ridges or "wrinkles". In many cases, these deformities also caused unwanted paint to accumulate or "puddle" to form around the holes. As a result, the ink drop trajectory (defined above) was adversely affected, thus causing print quality to deteriorate over time.

The present invention is designed to avoid the problems listed above while allowing thin-film polymeric orifice plate structures to be used in a highly effective manner. In addition, the benefits described here (including improved print quality over the life of the printhead) are obtained without applying additional layers of material to the orifice plate and / or chemical treatment of the latter.

As a preliminary point of information, the present invention will not be restricted to any specific types, sizes or arrangements of the printhead internal components unless otherwise stated herein. Likewise, the numerical parameters listed in this section and the following sections constitute preferred configurations designed to provide optimal results and do not limit the invention in any respect. The claimed invention and its new developments are applicable to all types of unrestricted printing systems as long as they include (1) at least one substrate as discussed above; (2) at least one ink ejector positioned over the substrate that, when activated, causes ink materials to be expelled on demand from the printhead; and (3) an orifice plate having one or more ink eject openings or "holes" therethrough and positioned above the substrate having ink ejector (s) thereon. The claimed invention is not to be considered "ink ejector specific" and is not limited to any particular ink applications, uses and compositions. Likewise, the term "ink ejector" should be interpreted to cover an ejector element or groups of multiple ink nozzles, regardless of shape, shape or configuration. Specific examples of various ink nozzles which may be used in connection with the invention will be listed below in the Detailed Description section of Preferred Settings. However, it is important to note that the present invention is especially suitable for use with ink supply systems employing thermal inkjet technology. In thermal inkjet printing units, at least one or more individual thin-film resistor elements are used as ink nozzles to selectively heat ink materials and expel them on demand from the printhead. Accordingly, the structures of the new orifice plate discussed below will be described in connection with thermal inkjet technology, it being understood that the invention should not be limited to this type of system. The claimed technology, instead, is possibly applicable to a wide variety of different printing devices as long as they again use the basic structures listed above, which include a substrate, at least one ink ejector on the substrate and a plate. nozzle positioned over the ink substrate / ejector (s).

It is to be understood that the claimed invention will not be restricted to any particular construction techniques (including any specific material deposition procedures or hole formation methods) unless otherwise stated in the Detailed Description of the Preferred Configurations. For example, the terms "forming", "application", "delivery", "placement" and the like as used throughout this discussion to describe the claimed printhead assembly and orifice plate will cover broadly any manufacturing procedures appropriate. These processes range from thin film manufacturing techniques to laser ablation methods and physical milling processes. In this regard, the invention is not to be considered "method-specific" unless otherwise stated herein. As previously noted, a highly effective and durable printhead is provided for use in an ink supply system. The term "ink supply systems" encompasses, without limitation, a wide variety of different devices, including "self contained" cartridge units, having an ink supply stored within them. Also encompassed by this term are "off-center" variety print units employing a printhead connected by one or more ink-conducting members to a remotely positioned ink containment unit in the form of a tank, vessel, housing, or other equivalent structure. Regardless of which ink supply system is employed in connection with the claimed printhead and orifice plate, the present invention is able to provide the benefits listed above, which include more efficient operation that facilitates high maintenance. print quality levels over extended periods of time.

The present invention, as described in this section, involves a special orifice plate structure produced from an organic polymer composition. The term "organic polymer" should be defined and used herein in a conventional manner. Organic polymers traditionally involve carbon-containing structures of repeated chemical subunits. Also, the terms "organic polymer" and "polymer" will generally be used in an unrestricted form to mean a structure that is optimally produced from one or more plastic type compounds, examples of which will be provided below. However, the present invention will not be restricted to any specific plastic / polymeric compounds associated with the claimed orifice plate (or orifice plate sizes, shapes and configurations) as long as the orifice plate structures are capable of providing paint materials. , in an exact and consistent manner.

The following discussion provides a brief and general overview of the invention. More specific information involving particular configurations, better modes, and other important aspects of the invention will be re-listed in the Detailed Description section of the Preferred Configurations presented below. All scientific terms used throughout this discussion should be interpreted in accordance with the traditional meanings ascribed to them by those skilled in the art to which this invention pertains unless a special definition is provided herein.

The claimed invention involves a highly specialized printhead using a new orifice plate structure. The orifice plate (which is made from at least one organic polymer composition) is highly durable and resistant to the effects of physical contact with a number of objects including, but not limited to, wiper units, which are commonly found in cleaning systems. conventional printing. As a result, the orifice plate and resulting printhead are characterized by increased reliability levels and the prevention of "shrinkage" or other deformation problems. These objectives are accomplished by providing a "recessed" orifice plate design, wherein the "main" ink eject opening associated with each orifice through the plate is positioned beneath the upper surface of the plate, so that the wipers ( or other physical structures) that may come into contact with the orifice plate do not directly engage this opening. The opening is therefore protected from the effects of physical abrasion and is capable of maintaining its full geometric and structural integrity. This design also prevents the formation of excess ink "puddles" on the top surface of the orifice plate around the nozzles so that the correct ink drop trajectory is maintained. As discussed below, this "inline" configuration is achieved by providing a special "recess" (e.g., an indentation / indented region) over each ink transfer hole through the plate (described in more detail below). Each recess begins at the top surface of the orifice plate and extends inwardly within the orifice plate.

More detailed information will now be provided with reference to the specific structures discussed above, and it should be understood that specific information regarding the orifice plate, building materials, dimensions and other operating parameters will be provided again in the Detailed Description sections of the Preferred Settings. In this regard, the present summary is intended to convey an overview of the invention and should not limit the invention in any way.

In accordance with the present invention, a printhead is provided for use in an ink supply system. As previously noted, the printhead generally includes a substrate having at least one ink ejector thereon (or directly on the substrate surface, or supported by the substrate with one or more layers of intermediate material therebetween). with both of these alternatives being considered equivalent and included in the language of the present claims). Many different ink nozzles can be used for this purpose without restriction, although thin film resistor elements that are typically used in thermal inkjet printing systems are preferred. Although the claimed invention is described here again, with primary reference to thermal inkjet technology, for the sake of clarity and convenience, it should not be limited in this regard. Next, a new orifice plate member (or, more simply, an "orifice plate") is provided which is made of at least one organic polymer composition (e.g., plastic). This orifice plate is of the generic type described above and specifically described in U.S. Pat. No. 5,278,584 to Keef et al. And 5,305,015 to Schantz et al. As well as to the co-pending U.S. Patent Application no. 08 / 921,678 (filed 08/28/97) entitled "IMPROVED PRINTHEAD STRUCTURE AND METHOD FOR PRODUCING THE SAME" (Meyer et al.), All incorporated herein by reference.

The orifice plate (which is fixedly positioned above and above the substrate comprising the ink ejector thereon) includes an upper surface and a lower surface. The term "upper surface" as used and claimed herein is defined to encompass the specific surface associated with the orifice plate that is outermost to the printhead and in practice constitutes the "outer" surface of the plate. nozzle / printhead that is exposed to the outside (outside) environment. This is the last "surface" through which ink will pass its path to the selected print media. Likewise, it is the surface that is "cleaned" using one or more cleaning members that are employed in conventional printing units, as described, for example, in U.S. patent no. 5,786,830 to Su et al. Which is likewise incorporated herein by reference.

In contrast, the bottom surface of the orifice plate is the specific surface that is positioned inside (e.g. inside) of the printhead and is the initial surface of the orifice plate through which ink enters as it is expelled. The bottom surface is the innermost (e.g. "unexposed") surface of the orifice plate which is in practice located between the upper surface of the orifice plate and the substrate having the ink ejector (s) thereon. . Finally, it is the specific orifice plate surface that is actually adhered to the underlying printhead components, including the ink barrier layer, as discussed in more detail below. Having introduced these specific definitions of the top and bottom orifice plate surfaces that define the orientation of the orifice plate relative to the rest of the printhead, the new aspects of the orifice plate will now be discussed.

In a preferred embodiment, at least one "recess" (or indentation / indentation region) is provided in the orifice plate beginning at its upper surface and ending in a position within the orifice plate between the upper and lower surfaces within. of the main board structure. The recess includes an upper end, a lower end, and a side wall therebetween, which defines the internal boundaries of the recess. The transverse sectional configuration of the recess (discussed in detail below) may involve many different non-limiting configurations including, but not limited to those which are square, triangular, oval-shaped and circular (preferred). The upper end of the recess in the upper surface of the orifice plate has a first opening, with the lower end of the recess comprising a second opening. The first opening is larger than the second opening, with the second opening being "embedded" according to the design described above. The built-in location of the second aperture (which actually functions as the "main aperture" through which ink passes during image generation) provides the benefits listed above. Because of its built-in and "protected" location, it is not subject to physical damage and "cracking" caused by physical abrasion and external forces. Another important feature of the recess in a preferred embodiment is the structural relationship wherein the sidewall described above is oriented at an angle of about 90 ° (approximately a right angle) to the upper surface of the orifice plate member. This design provides a high degree of structural integrity and enables any physical forces applied to the upper surface (first opening) of the orifice plate to be effectively confined to this region without being substantially transmitted downwardly into the recess and second opening. As a result, the overall integrity and planar geometry of the second aperture (and surrounding structures) is maintained so that proper ink drop trajectory can occur over the life of the printhead. Also, the recess is either partially or (preferably) in complete axial alignment with the ink transfer hole under it (and vice versa), with the ink transfer hole being described in more detail below. Specifically, the longitudinal geometric axes associated with both the recess and the hole are in alignment with each other and are contiguous, as shown in the drawing figures in the next section).

At this point additional explanatory information is provided regarding the relationship between the first opening and the second opening, the first opening being "larger in size" than the second opening. The term "larger in size" basically involves a situation in which the transverse sectional area of the first aperture exceeds the transverse sectional area of the second aperture, with the term "area" being conventionally defined according to the shape of the aperture under consideration. For example, in situations involving a square or rectangular opening, the transverse sectional area will involve the length of the opening multiplied by its width. With reference to the first and / or second openings, which are circular, their transverse sectional area will be defined conventionally to encompass the formula "Ttr2", where r = the radius of the circular aperture. Also, conventional formulas that are used to calculate the area of other shapes (ovals, triangles, etc.) may be employed to determine the size of the first and / or second openings.

In situations involving the first and second circular apertures (which are preferred for numerous reasons, including ease of production, absence of angled surfaces, etc.), the term "larger in size" may also involve a comparison of respective values of the diameter of the openings. In an optimal configuration designed to provide effective results, the first opening and the second opening, as previously defined, both have circular cross-section, with the first opening having a first diameter and the second opening having a second diameter. In this specific embodiment, the first diameter of the first aperture is preferably at least about 40 μπι or longer (e.g., larger / longer) than the second diameter of the second aperture. However, the present invention is not restricted to this numerical variation or any other numerical parameters unless otherwise stated herein.

According to the present invention, the first aperture must be larger than the second aperture for a number of reasons. By providing a first opening in the upper surface of the orifice plate, which is larger in size than the second opening, the transmission of disruptive physical forces from the upper surface (i.e. the first opening) to the second opening within the recess is again minimized according to the structural relationship described above. Although the exact physical mechanism by which this benefit is obtained is not fully understood, it represents a new and important aspect of the invention. Also, the size ratio described above, wherein the first aperture is larger in size than the second aperture, still facilitates proper ink drop trajectory. Any deformations at the peripheral edges of the first opening on the top surface of the orifice plate that are caused by cleaning or other physical abrasion will not adversely affect the drop of paint leaving the second opening in the recess, given the larger size of the first opening, relative to a (1) to the second aperture; and (2) the ink drop passing therethrough (with the size of the ink drop being imposed substantially by the size of the second opening within the recess). Because the ink droplet is smaller than the first opening on the top surface of the orifice plate, the droplet will not substantially engage any of the edges associated with the first opening and therefore will not be affected by any deformities (e.g. , "wrinkles") at its peripheral edges.

Further, the present invention will not be restricted to any specific sizes or shapes associated with the recess, first aperture and second aperture. While all of these structures within a given hole are preferably uniform in cross-sectional shape (e.g., circular, square, etc. from first end to second end), it is also considered that the recess and its various components could have shapes different cross-sectional sections in various positions. For example, the first opening at the first end of the recess could have a substantially circular cross section, while the second opening at the second end could have square cross section, although a uniform design is preferred again and will be emphasized in the remainder of this discussion.

For optimal results in a representative non-limiting configuration of the claimed orifice plate, the claimed recess will further comprise a lower wall at the second end of the recess. The second opening described above passes through the lower wall. The lower wall has a preferably planar configuration and substantially parallel to the upper surface of the orifice plate. Also, the bottom wall is preferably oriented at an angle of about 90 ° (approximately a right angle) to the recess sidewall. As noted above, the recess sidewall is optimally oriented at an angle of about 90 ° (approximately a right angle) to the upper surface of the orifice plate member. In this embodiment, where both right-angle relationships described above are employed in combination, the recess will be substantially cylindrical, or disc-shaped, as shown in the accompanying drawing figures. This design provides an especially high degree of structural integrity, creep resistance, and the ability to maintain proper ink drop trajectory over time. However, the claimed recess should not be limited to the angular relations provided above, which constitute the embodiments provided by way of example. In situations involving the use of a recess having a lower wall as previously described, many other variations are possible within the scope of the invention as long as the claimed recess is produced having the desired functional capabilities. For example, as clearly shown in the accompanying drawing figures and described in the Detailed Description of the Preferred Configurations presented below, a number of different angular relationships are contemplated, involving the sidewall, bottom wall and top wall of the orifice plate in mutual relationship. . For example, as illustrated in the accompanying drawing figures, the sidewall associated with the recess may actually be oriented at an angle greater than approximately 90 ° to the upper surface of the orifice plate.

Specifically, the angular relationship between the recess sidewall and the upper surface of the orifice plate may involve: (1) an angle of about 90 ° (approximately a right angle); or (2) an "obtuse" angle, i.e. an angle exceeding 90 ° (but less than 180 °), with a non-limiting upper limit, preferably around 145 °. Likewise, the lower wall at the second end of the recess (through which the second aperture passes) may be oriented at an angle of about 45 to 165 ° with respect to the side wall of the recess. Despite the dual 90 ° angle ratio between (A) the sidewall and the upper surface of the orifice plate; and (B) the bottom wall of the recess and the side wall which produces a cylindrical or disc-shaped recess is again preferred, the various angular values listed above (or others) may also be employed in multiple combinations without limitation. . The selection of any of the given dimensions, angles and the like in the present invention will be determined, according to the preliminary preliminary pilot test, taking into account numerous factors, ranging from the types of building materials associated with the slabs. the way the printheads will be used.

Having described the new recess provided in the claimed orifice plate (which offers numerous benefits including, but not limited to, the creation of a "built-in" paint eject opening that is resistant to deformation caused by physical abrasion, cleaning, etc.), the remaining portions of the hole that reside beneath the recess will now be discussed. Positioned below the recess and in fluid communication with the latter, there is an ink transfer hole. The ink transfer hole is in axial alignment, partially or (preferably) complete with the recess and vice versa as previously discussed. As a result, ink materials expelled from the ink ejector (s) will pass up through the hole through the recess on the top surface of the nozzle plate and out of the printhead to provide media. print media (made of paper, metal, plastic and the like). To accomplish this and from a functional point of view, the ink transfer hole begins at the second end of the recess (e.g., the second aperture thereof) and ends at the bottom surface of the orifice plate member. The ink transfer hole is the first structure within the orifice plate to actually receive the ink materials during the expulsion process, with the ink then passing through the hole and recess to finalize delivery, as previously noted.

Although a number of different structural designs may be employed in connection with the paint transfer hole, as described below in the Detailed Description section of the Preferred Configurations, the hole optimally has a uniform cross section over all its length. Likewise, the hole includes a sidewall, which is preferably oriented at an "acute" angle (less than 90 °), relative to the upper surface of the orifice plate member, to form a substantially "shaped" structure. cone". This design promotes quick and complete ink entry into and through the orifice plate.

However, other sidewall designs may be employed in connection with the paint transfer hole including, but not limited to, those forming an angle of about 90 ° (approximately a right angle) or more to the upper member surface. of the orifice plate. The selection of any given internal design relative to the claimed paint transfer hole can be re-determined using the preliminary preliminary pilot test.

Additional data involving printhead assembly techniques and other related information will be set forth below (including a variety of construction methods that can be used to fabricate the various structural aspects of the orifice plate). For example, representative construction methods that can be employed to produce the claimed ink transfer hole and recess range from laser ablation methods to chemical etching and physical processing techniques in which piercing devices are used. used. Accordingly, a number of conventional procedures may be employed without limitation to the purposes described above. It should be emphasized that many different printhead components, ink nozzles, size parameters and the like are applicable to the present invention as long as the new orifice plate is used as part of the basic printhead structure. This orifice plate again provides improved durability and proper ink drop trajectory control. In addition to the new orifice plate described herein, an improved "ink supply system" is also provided, in which an ink containment vessel is operatively connected to and in fluid communication with the claimed printhead discussed above. As discussed extensively in the Detailed Description section of Preferred Configurations, the term "operatively connected" with respect to the printhead and ink containment vessel will involve a number of different situations including, but not limited to the use of (1). ) "self contained" cartridge units wherein the ink holding vessel is attached directly to the printhead to produce a system having an "onboard" ink supply; and (2) "off-center" variety printing units employing a printhead connected by one or more conductive members (or similar structures) to a remotely positioned ink containment unit in the form of a tank, vessel , housing or other equivalent structure. The novel orifice plates and printheads of the present invention are not restricted to use with any specific ink containment vessels, the proximity of these vessels to the printheads, and the means by which the vessels and printheads are attached to each other. to others.

Finally, the invention will also encompass a method for producing the claimed highly efficient heads. The manufacturing steps for this purpose involve the materials and components listed above, with the previously described summary of these items being incorporated by reference in this discussion. The basic steps of production are as follows: (1) providing an orifice plate having the aspects listed above (and incorporated herein by reference); (2) providing a substrate comprising at least one ink ejector thereon, as previously noted; and (3) securing the orifice plate member

fixed at and above the substrate to produce the printhead. In a preferred embodiment, the orifice plate will have a recess with a sidewall that is oriented at an angle of about 90 ° (approximately a right angle) to the upper surface of the plate and / or a lower wall in the second end of the recess, which is substantially parallel to the upper surface. Other variations are possible, as noted above, with the claimed orifice plate not being restricted to the specific aspects listed in this section. Similarly, it should be noted that recess fabrication within the upper surface of the orifice plate can be ensured before or after fixing the orifice plate in position on the underlying portions of the printhead, with both techniques being considered. equivalent.

Accordingly, any statements set forth herein that indicate that an orifice plate having the claimed aspects (including recess) is "provided" will equivalently encompass both of the alternatives listed above.

The present invention represents a significant advance in the field of thermal inkjet technology and high quality imaging with improved reliability, speed and longevity. The novel structures, components and methods described herein offer many important benefits including, but not limited to (1) a substantial increase in printhead / orifice plate longevity; (2) the ability to maintain precise control over ink drop trajectory over the life of the printhead; (3) compatibility of the claimed orifice plate with printing units, which employ a variety of different cleaning systems which are used to clean the printhead; (4) the prevention of premature orifice plate damage, despite its polymeric thin film characteristic; (5) the ability to provide a thin film polymeric orifice plate structure that can maintain its thin and light profile, while avoiding the problems discussed above; and (6) achieving these objectives using a technique that avoids the layering of additional material and / or chemical compositions on the orifice plate which may increase the cost, complexity and overall manpower requirements associated with the manufacturing process. printhead. These and other benefits, objects, aspects and advantages of the invention will now be discussed below in the Brief Description of the Drawings and Detailed Description of the Preferred Configurations. In addition to the above, other embodiments of the present invention may be summarized broadly as follows. In one embodiment, a printhead for use in an ink supply system includes a substrate having at least one ink ejector thereon. An orifice plate member is positioned over and above the substrate. The orifice plate member has at least one ink transfer hole extending therethrough. The orifice plate member further includes: an upper surface defining an upper opening for the ink transfer hole, a lower surface defining a lower opening for the ink transfer hole and a recess in the upper surface. The drawdown is non-concentric with the ink transfer hole. And the drawdown is in fluid communication with the ink transfer hole. By providing a non-concentric counterbore on the upper surface of the orifice plate member, the present invention is capable of controlling the tail peeling of the expelled inkjet droplets and thus eliminating the puddle problems associated with jet printing mechanisms. of prior art thermal ink.

In another embodiment, the ink transfer hole defines at least one sidewall. And, when the upper surface of the orifice plate member is countersunk, at least a portion of the sidewall is removed, so that at least a portion of the sidewall is thicker than at least another portion of the sidewall. Therefore, this configuration can also be used to control the inkjet droplet trajectory and thereby eliminate the problems of the prior art.

In an additional configuration, the undercut is deep enough to retain the meniscus and drive any ink pools back to the ink transfer hole. This minimizes and / or prevents overflow of the meniscus and therefore improves ink droplet tail detachment control. In yet another embodiment, the orifice plate member includes a partial lowering rather than a complete lowering. Partial lowering defines a countersunk portion of the upper surface and an unabated portion of the upper surface. The undercut portion is in fluid communication with the ink transfer hole. The unremoved portion attracts ink as it is supplied from the printhead. This improves ink droplet tail detachment control and eliminates the limitations of the prior art.

In yet another embodiment, lowering on the upper surface creates a smooth, even edge around the ink transfer hole to minimize fractions on the upper surface. The undercut may also surround, at least partially, the edge around the ink transfer hole. This setting also increases ink droplet tail detachment control and eliminates the limitations of the prior art.

Of course, the printheads, print cartridges, and methods of these configurations may also include other components and / or additional steps. Other configurations are also described and claimed herein.

Brief Description of the Drawings

The present invention may take physical form in some parts and steps, and their configurations will be described in detail in this specification and illustrated in the accompanying drawings in which: Figure 1 is a schematically illustrated exploded perspective view of a representative ink supply system in the form of an ink cartridge that is suitable for use with the components and methods of the present invention. The ink cartridge of Figure 1 has an ink containment vessel attached directly to the claimed printhead of the invention so that an "onboard" ink supply is provided.

Figure 2 is a schematically illustrated enlarged partial cross-sectional view of the printhead used in the ink cartridge unit of Figure 1, with a conventional orifice plate structure being employed.

Figure 3 is a schematically illustrated perspective view of an ink containment vessel used in an alternate "off-center" ink supply system which may be similarly operatively connected to the printhead. of the present invention.

Figure 4 is a partial cross-sectional view of the ink containment vessel shown in Figure 3 taken along line 4-4.

Figure 5 is an enlarged partial cross-sectional schematic view of an organic polymer based thin film orifice plate structure showing one of the holes through the plate in a preferred embodiment of the present invention.

Figure 6 is a top view of the orifice plate structure of Figure 5 looking down into the claimed recess.

Figure 7 is an enlarged partial cross-sectional schematic view of an organic polymer-based orifice plate structure showing one of the holes through the plate in an alternative embodiment.

Figure 8 is an enlarged partial cross-sectional schematic view of an organic polymer-based orifice plate structure showing one of the holes through the plate in another alternative embodiment.

Figure 9 is an enlarged partial cross-sectional diagrammatic view of an organic polymer based orifice plate structure showing one of the holes through the plate in yet another alternative embodiment.

Figure 10 is an enlarged partial cross-sectional view, schematically illustrated, of an organic polymer-based orifice plate structure showing one of the holes through the plate in yet another alternative embodiment.

Figure 11 is an enlarged partial cross-sectional view, schematically illustrated, of an organic polymer-based orifice plate structure showing one of the holes through the plate in an even further alternative configuration. Figure 12 is an enlarged partial cross-sectional view of an organic polymer-based thin film orifice plate structure showing a typical counterbore profile and concentric bore outlet located within the counterbore.

Figure 13 is an enlarged partial cross-sectional view of an organic polymer-based thin-film orifice plate structure showing a preferred embodiment of the present invention in which recess and bore outlet are not concentric. Figure 14 is an enlarged partial cross-sectional view of an organic polymer-based thin film orifice plate structure showing a preferred embodiment of the present invention wherein the undercut is circular and deep enough to retain the ink meniscus .

Figure 15 is an enlarged partial cross-sectional view of an organic polymer-based thin film orifice plate structure showing a preferred embodiment of the present invention in which the recess is non-circular and deep enough to retain the meniscus of ink.

Figure 16 is an enlarged partial cross-sectional view of an organic polymer-based thin film orifice plate structure showing a preferred embodiment of the present invention in which a partial undercut defines a partially asymmetrical bore outlet.

Figure 17 is a top view of the orifice plate structure of Figure 16 looking down into the recess.

Figure 18 is an enlarged perspective view of a prior art bore in an organic polymer-based thin film orifice structure created by laser ablation.

Figure 19 is an enlarged perspective view of a shallow ablation created by laser ablation in an organic polymer based thin film orifice structure.

Figure 20 is an enlarged perspective view of a shallow ablation created by laser ablation in an organic polymer based thin film orifice structure.

Figure 21 is an isometric drawing of a typical printer that may employ an inkjet print cartridge using the present invention; and Figure 22 is a schematic representation of a printer which may employ the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides, inter alia, new designs and methods of manufacturing an inkjet printhead capable of printing varying amounts of ink drop weight. In particular, this invention eliminates the problems of the prior art by preferably etching a substrate to provide firing chambers with different orifice layer thicknesses. This provides varying distances between the ink energizing elements in the firing chambers and their corresponding holes. Alternatively, the invention may use different volume firing chambers, different size ink energizing elements and / or laterally displaced ink energizing elements. Therefore, by decreasing the distance between the nozzles and their ink energizing elements, providing different volume firing chambers, providing differently sized ink energizing elements and / or laterally displaced ink energizing elements from their corresponding holes, A manufacturer may provide inkjet printheads, capable of printing varying amounts of ink drop weight.

The present invention involves a unique printhead for a single ink supply system including a specialized orifice plate through which ink passes. Ink is therefore supplied to a selected print media material (paper, metal, plastic and the like) using conventional printing techniques. Thermal inkjet printing systems are especially suited for this purpose. They employ at least one or more thin film resistor elements on a substrate, which selectively heats and expels ink on demand. The claimed invention will be described in this section with primary reference to thermal inkjet technology. However, it should be understood that the invention is also applicable to other ink supply systems as long as they include a substrate, at least one ink ejector over the substrate and an orifice plate positioned over the ink substrate / ejector. Other representative ink nozzles will be listed below for reference purposes.

The claimed printheads include a orifice plate with multiple openings therethrough. The orifice plate is made of a non-metallic organic (e.g. plastic) polymer film with the specific examples also given below.

To increase the durability of this structure, the orifice plate includes a new orifice design that avoids a problem known as "puckering" or "puckering". This condition occurs when the orifice plate surface (i.e. the upper surface as defined herein) comes into contact with an object that "rubs" or otherwise traverses the surface in a physically engaging manner. For example, "puckering" may occur when a thin-film polymeric orifice plate is "cleaned" by an elastomeric wiper element of the type shown in U.S. Patent No. 4,245,111. 5,786,830 to Su et al.

As discussed in more detail below, "puckering" the orifice plate causes raised "wrinkle" structures to form along the peripheral edges of the holes. This physical deformation of the orifice plate (and the resulting change in orifice geometry / planarity) can cause significant changes in the ink drop path, that is, the path that the ink drop must follow in order to create the final printed image. . These undesirable changes in orifice plate geometry prevent ink droplet travel in the desired direction. Instead, the droplet is expelled inappropriately and is delivered to an unwanted location in the print media material. Deformation of the orifice plate as described above (including the creation of extraneous "wrinkle" structures around the peripheral edges of the orifices) may also cause ink "puddle" to accumulate or form in these regions. This may also alter the ink drop trajectory by causing an undesired interaction between the ink drop being expelled (particularly the end portion of each drop or its "tail") with the accumulated ink adjacent the holes.

As a result, print quality deterioration occurs over time. These problems are again caused by two main factors, namely (1) the flexible, thin nature of the organic polymer orifice plates described herein; and (2) the physical forces imposed on the orifice plates by conventional wiping structures (or other objects that may come into contact with them).

To solve these problems, a new orifice design is employed on the claimed orifice plate. Specifically, the "main aperture" (defined below) directed into the hole is "recessed" by providing this aperture within a "recess". The recess begins at the upper surface of the plate and ends at a position within the plate between the upper and lower surfaces. By "isolating" this opening, as indicated above, it is "protected" from damage caused by ink wipers and other structures passing over the top surface of the orifice plate. In this way, "frowning" ink path problems are avoided. The claimed invention therefore represents a significant advance in printing technology, with the benefits and specific details of it being described below. As previously noted, the present invention will be described herein with primary reference to thermal inkjet technology. The term "thermal inkjet printhead", as used entirely in this discussion, should be broadly interpreted to encompass, without limitation, any type of printhead having at least one heat resistor, which is used to excite thermally ink materials for delivery to a print media material. In this regard, the invention will not be limited to any specific designs of thermal inkjet printheads, with many different internal component structures and arrangements being possible, provided that they include the resistor elements mentioned above, which expel ink on demand using the thermal processes. Also, the invention will not be restricted to any specific printhead structures, inkjet technologies or types, except as otherwise stated herein and is likely to apply to many thermal inkjet systems as well as systems employing other technologies that do not use thermal inkjet devices.

The claimed printheads and orifice plates are also applicable to many different ink supply systems, as previously stated, including (1) onboard cartridge units having a self contained ink supply, which is operatively connected to and in fluid communication. with the printhead; and (2) "off-center" units employing a remotely positioned ink containment vessel that is operatively connected to and in fluid communication with the printhead using one or more fluid transfer conduits. The printhead described below should therefore not be considered "system specific" with reference to the ink storage devices associated with it.

To provide a clear and complete understanding of the invention, the following detailed description will be divided into seven sections, namely, (1) "A. An Overview of Printhead Technology"; (2) "B. The New Orifice Plate Structures of the Present Invention"; (3) "C. Ink Supply Systems using the New Printheads / Orifice Plates and Associated Manufacturing Methods"; (4) "D. Non-Concentric Reaming of an Orifice"; (5) "E. Deep Reaming of a Hole"; (6) "F. Partial Reaming of a" Hole "; and (7)" G. Ablation of Exit Side of Exit Edge of Hole in Hole ".

A. An Overview of Printhead Technology

As noted above, the present invention is applicable to a wide variety of ink cartridge printheads, including (1) an orifice plate member having one or more apertures therethrough; and (2) a substrate under the orifice plate member comprising at least one or more ink "ejectors" thereon or associated therewith. The term "ink ejector" will be defined to encompass any type of component or system that selectively ejects or expels ink materials from the printhead through the plate member. Thermal inkjet printing systems that use multiple heat resistors as ink nozzles are preferred for this purpose. However, the present invention will not be restricted to any specific type of inkjet or inkjet printing system as noted above. Instead, a number of different ink supply devices may be encompassed by the invention including, but not limited to, the generic type piezoelectric drop systems described in U.S. Patent no. No. 4,329,698 to Smith, dot matrix systems of the variety described in U.S. Patent no. No. 4,749,291, to Kobayashi et al., As well as other comparable and functionally equivalent systems designed to deliver ink using one or more ink nozzles. Specific ink ejecting devices associated with these alternative systems (e.g., the piezoelectric elements in U.S. Patent No. 4,329,698) will be encompassed by the term "ink nozzles" as discussed above. Accordingly, although the present invention is discussed herein, with primary reference to thermal inkjet technology, it should be understood that other systems are equally applicable and relevant to the claimed technology.

To facilitate a complete understanding of the present invention, as long as it applies to thermal inkjet technology (which is the preferred system of primary interest), an overview of this technical field will now be provided. The ink supply systems shown schematically in the figures of the above related drawings (e.g. figures 1 to 4) are provided for example purposes only and are not limited.

Referring to Figure 1, a representative thermal inkjet cartridge 10 is illustrated. This cartridge is of a generic type shown and described in U.S. patent no. 5,278,584, to Keefe et al. And in the "Hewlett-Packard Journal", vol. 39, no. 4 (August, 1988), both incorporated herein by reference. It is again emphasized that the cartridge 10 is shown in schematic format, with more detailed information regarding the cartridge 10 being provided in U.S. 5,278,584. As shown in Figure 1, the cartridge 10 first includes a housing 12, which is preferably made of plastic, metal or a combination of both. The housing 12 further comprises an upper wall 16, a lower wall 18, a first side wall 20 and a second side wall 22. In the embodiment of Figure 1, upper wall 16 and lower wall 18 are substantially parallel to each other. Similarly, the first sidewall 20 and the second sidewall 22 are also substantially parallel to each other.

The housing 12 additionally includes a front wall 24 and a rear wall 26, which is optimally parallel to the front wall 24. Surrounded by the front wall 24, upper wall 16, lower wall 18, first side wall 20, second sidewall 22 and rear wall 26 is an inner chamber or housing 30 within housing 12 (shown in dashed lines in figure 1) which is designed to hold an ink supply therein. Many compositions may be used in connection with the ink including, but not limited to, those listed in U.S. Patent No. 4,245,111. 5,185,034 to Webb et al., Which is incorporated herein by reference. The front wall 24 further includes an outwardly positioned printhead support structure 34 which comprises a substantially rectangular central cavity 50 therein. The central cavity 50 includes a lower wall 52 shown in Figure 1 with an ink outlet port 54. The ink outlet port 54 traverses the housing 12 entirely and, as a result, communicates with the housing 30 inside. housing 12 so that ink materials can flow out of housing 30 through ink outlet port 54.

Also positioned within the central cavity 50 is an outwardly extended mounting frame 56, the function of which will be discussed below. As schematically shown in Figure 1, the mounting frame 56 is substantially uniform (flush) with the front face 60 of the printhead support frame 34. The mounting frame 56 specifically includes two elongated sidewalls 62, 64 which Similarly, they will be described in more detail below. Still with reference to figure 1 fixedly attached to the housing 12 of the ink cartridge unit 10 (for example, attached to the extended outward printhead support structure 34) is a printhead generally designated in the figure 1, reference numeral 80. For purposes of the invention and according to conventional terminology, printhead 80 actually comprises two main components fixedly attached together (with some subcomponents positioned therebetween). These components and additional information concerning printhead 80 are again described in U.S. 5,278,584, by Keefe et al., Which discusses the ink cartridge in considerable detail. The first major component used to produce the printhead 80 consists of a substrate 82 preferably made of silicon [Si] or other conventional materials known in the art for this purpose. Fixed and positioned on the upper surface 84 of substrate 82 using standard thin-film manufacturing techniques, multiple individually energized thin-film resistors are provided, which function as "ink nozzles" and are preferably made of a tantalum-based composition. aluminum [TaAl}, known in the art for resistor manufacturing. Only a small number of resistors 86 are shown in the representation of Fig. 1, with resistors 86 being presented in enlarged schematic format for clarity. Also, it should be noted that any statements provided herein involving the use of a substrate having at least one ink ejector thereon will encompass a situation where (1) the ink ejector is attached directly to and onto the substrate surface without intervention. of layers of material between them; or (2) the ink ejector is supported by the substrate (e.g. positioned on it), with one or more layers of intermediate material being positioned between the substrate and the ink ejector, with both of these alternatives being considered equivalent and within the present claims. For example, conventional thermal inkjet systems may actually employ an electrically insulating base layer made of silicon dioxide (SiO2) on the substrate, with resistor elements being placed on the base layer. Therefore, the placement of the selected ink nozzles (eg, the nozzles 86) on a given substrate should be considered again to cover both alternatives described above.

Also provided on the upper surface 84 of substrate 82, using conventional photo lithographic / metallization techniques, is a plurality of metallic conductive traces 90 which electrically communicate with resistors 86. Conductive traces 90 also communicate with multiple contact regions, metal pad type 92 positioned at the ends 94, 95 of substrate 82 on top surface 84. The function of all these components which, in combination, are collectively referred to herein as a resistor assembly 96, will be discussed in more detail below. Many different materials and design configurations can be used to construct resistor assembly 96, with the present invention not being restricted to any specific elements, materials and components for this purpose. However, in a preferred, representative and non-limiting embodiment, discussed in U.S. Patent no. 5,278,584, to Keefe et al., Resistor assembly 96 will be approximately 0.5 inches (1.3 cm) long and will also contain 300 resistors 86, thus enabling a resolution of 600 dots per inch. ("dots per inch", "DPI"). The substrate 82, containing the resistors 86 thereon, preferably will have a width "W" (Figure 1) that is less than the distance "Q" between the sidewalls 62, 64 of the mounting frame 56. As a result, the Ink flow walkways 100, 102 (shown schematically in Figure 2) are formed on both sides of the substrate 82 so that the ink flowing from the ink outlet port 54 in the central cavity 50 can finally contact the resistors 86, as discussed below.

It should also be noted that substrate 82 may include a number of other components thereon (not shown), depending on the type of ink cartridge 10 under consideration. For example, substrate 82 may also include a plurality of logic transistors for precisely controlling the operation of resistors 86, as well as a conventionally configured "demultiplexor" as described in U.S. Patent No. 4,245,138. 5,278,584. The demultiplexor is used to "demultiplex" the incoming multiplexed signals and then distribute these signals to the various thin film resistors 86. Using a demplexiplex for this purpose enables a reduction in the complexity and quantity of the circuitry (eg contact regions 92 and traces 90) formed on substrate 82. Other aspects of substrate 82 (e.g. resistor assembly 96) will be presented herein. Fixed at the position above substrate 82 and resistors 86 (with a number of layers of interleaving material between them, including an ink barrier layer and an adhesive layer, in the conventional design of Figure 1, as further discussed below). ) is the second major component of printhead 80. Specifically, a nozzle plate 104 of conventional design (compared to the new structure of the claimed invention) is provided which is used to distribute the selected ink compositions to a stock material. designated print media (made of paper, metal, plastic and the like). The designs of the anterior orifice plate involved a rigid plate structure made of an inert metal composition (eg, gold-plated nickel). However, recent developments in thermal inkjet technology have resulted in the use of organic, non-metallic polymer films to construct orifice plate 104. As illustrated in Figure 1, this type of orifice plate 104 will consist of an elongated film member. flexible thin 106, fabricated from a selected organic polymer film product that may or may not (preferred) include metal atoms within or attached to the basic polymeric structure. The term "organic polymer" will be defined in a conventional manner. Organic polymers basically involve carbon-containing structures of repeated organic chemical subunits. A number of different polymeric compositions may be employed for this purpose, with the present invention not being restricted to any specific building materials. For example, orifice plate 104 may be manufactured from the following compositions: polytetrafluoroethylene (e.g., Teflon®), polyimide, polymethyl methacrylate, polycarbonate, polyester, polyamide, polyethylene terephthalate, or mixtures thereof. Also, a representative commercial (e.g. polyimide-based) organic polymer composition that is suitable for the construction of orifice plate 104 / elongate member 106 is a product sold under the trademark "KAPTON" by El du Pont de Nemours & Company of Wilmington, DE (USA). Orifice plate structures produced from the non-metallic compositions described above are typically uniform in thickness and highly flexible. Likewise, they provide numerous benefits ranging from reduced production costs to a substantial simplification of the overall printhead architecture, which translates into increased reliability, economy and ease of manufacture. As shown in the schematic illustration of FIG. 1, flexible orifice plate 104 is designed to "engage" the extended printhead support structure 34 in the finished ink cartridge 10.

The thin film-like elongate member 106 that is used to form the orifice plate 104 further includes an upper surface 110 and a lower surface 112 (Figures 1 and 2). Formed on the bottom surface 112 of orifice plate 104 and shown in dashed lines in Figure 1 is a plurality of metallic circuit traces 114 (e.g. copper), which is applied to the bottom surface 112 using known metal deposition techniques. lithographic photo. Many different circuit trace patterns may be employed on the lower surface 112 of the elongate member 106 (orifice plate 104), with the specific pattern depending on the particular type of ink cartridge 10 and printing system under consideration. Also provided at position 116, on top surface 110 of orifice plate 104 are a plurality of metal contact pads (e.g. gold plated copper) 12 0. Contact pads 120 communicate with circuit traces 114 bottom surface 112 of the plate 104 through openings or "pathways" (not shown) through the elongate member 106. While using the ink cartridge 10, in a printing unit, the pads 120 contact each other. corresponding printer electrodes so as to transmit electrical control signals from the printer unit to the contact pads 120 and circuit traces 114 on orifice plate 104, finalizing the supply to resistor assembly 96. Electrical communication between the assembly resistor 96 and orifice plate 104 will be discussed below.

Positioned within the middle region 122 of the elongate member 106 used to produce the orifice plate 104 is a plurality of openings or holes 124, which pass entirely through the plate 104. These holes 124 are shown in enlarged form in figures 1 to 2. In the complete printhead 80, all the components listed above are mounted (discussed below) so that each of the holes 124 is aligned with at least one of the resistors 86 (for example, "ink nozzles") on the substrate 82. As a result, energizing a particular resistor 86 will cause ink to be expelled from the desired hole 124 through the hole plate 104. In a representative configuration as shown in Figure 1, the holes 124 are arranged in two rows 126, 130. Also, if this arrangement of holes 124 is employed, resistors 86 in resistor assembly 96 (e.g. substrate 82) will also be used. arranged in two corresponding rows 132, 134, so that the rows 132, 134 of the resistors 86 are substantially coincident (e.g., in alignment) with the rows 126, 130 of the holes 124. Finally, as shown in figure 1, two windows 150, 152 are provided at each end of the rows 126, 130 of the holes 124. Partially positioned within the windows 150, 152 are the beam conductors 154, which, in a representative configuration, are gold-plated copper and constitute the The terminal ends (e.g., the ends opposite the contact pads 120) of the circuit traces 114, positioned on the bottom surface 112, of the elongate member 106 / orifice plate 104. Conductors 154 are designed for electrical connection by welding, bonding by thermo-compression, etc. contact regions 92 on the upper surface 84 of substrate 82 associated with resistor assembly 96. Attachment of conductors 154 to contact regions 92 on substrate 82 is facilitated during mass production manufacturing processes by windows 150, 152, that allow immediate access to these components. As a result, electrical communication is established from the contact pads 120 to the resistor assembly 96 by means of the circuit traces 114 in the orifice plate 104. Electrical signals from the printer unit (not shown) can then be transmitted by conductive traces 90 on the substrate 82 for resistors 86 so that on-demand heating (energization) of resistors 86 can occur. At this time, it is important to briefly discuss the manufacturing techniques in connection with the structures described above, which are used to manufacture the printhead 80. With reference to the orifice plate 104, all openings through it, including windows 150, 152 and holes 124 are typically formed using conventional laser ablation techniques, as discussed again in U.S. Pat. 5,278,584, to Keef et al. Specifically, a mask structure initially produced using standard type lithographic techniques is employed for this purpose. A conventionally designed laser system is then selected which, in a preferred embodiment, involves an excimer laser of a selected type from the following alternatives: F2, ArF, KrCl, KrF or XeCl. Using this specific system (along with preferred pulse energies greater than about 100 millijoules / cm2 and pulse durations less than about 1 microsecond), the openings listed above (for example, holes 124) can be formed with a high degree of accuracy, precision and control. Other methods are also suitable for producing the full orifice plate 104 / holes 124, including conventional ultraviolet ablation processes (e.g. using ultraviolet light in the range of about 150 to 400 nm) as well as conventional etching processes. chemistry, stamping, reactive ion etching, ion beam milling, mechanical drilling and similar known processes.

After the orifice plate 104 is produced, as discussed above, the printhead 80 is completed by securing the resistor assembly 96 (e.g. substrate 82 having resistors 86 thereon) to the orifice plate 104. In one embodiment Preferably, the manufacture of the printhead 80 is performed using automated ribbon binding ("TAB") technology. The use of this particular process to produce the printhead 80 is again discussed in considerable detail in U.S. Patent no. 5,278,584. Also, background information concerning TAB technology is also generally provided in U.S. 4,944,850 to Dion. In a TAB-type manufacturing system, the processed elongate member 106 (e.g. complete orifice plate 104), which has already been ablated and standardized with circuit traces 114 and contact pads 120, actually exists in the form of " "multiple" structures interconnected in an elongated "tape" with each "structure" representing an orifice plate 104. The tape (not shown) is then positioned (after cleaning in a conventional manner to remove impurities and other waste materials). ) in a TAB connector having an optical alignment subsystem. Such an apparatus is well known in the art and commercially available from many different sources including, but not limited to, Shinkawa Corporation of Japan (model No. II-20, or other comparable model). Within the TAB connector, the substrate 82 associated with resistor assembly 96 and orifice plate 104 are properly oriented such that (1) holes 124 are in precise alignment with resistors 86 on substrates 82; and (2) the beam-like conductors 154 associated with circuit traces 114 in orifice plate 104 are in alignment with and positioned against the contact regions 92 on substrate 82. The TAB-type connector then uses a method of " tandem connection ("gang bonding") (or other similar procedures) to press the conductors 154 over the contact regions 92 (which is accomplished through the opening windows 150, 152 in the orifice plate 104). The TAB coupling apparatus then applies heating according to conventional coupling processes to secure these components together. It is also important to note that other standard bonding techniques may also be used for this purpose including, but not limited to ultrasonic bonding, conductive epoxy bonding, solid paste application processes and similar methods. In this regard, the claimed invention should not be restricted to any specific processing techniques associated with printhead 80. As noted above in connection with the conventional ink cartridge 10 of Figure 1, additional layers of material are typically present between the plate. 104 and resistor assembly 96 (e.g. substrate 82 with resistors 86 thereon). These additional layers perform various functions, including electrical insulation, adhesion of orifice plate 104 to resistor assembly 96 and the like. Referring to Figure 2, the printhead 80 is shown schematically in cross section after attachment to the housing 12 of the cartridge 10, with attachment of these components being discussed in more detail below.

As shown in Figure 2, the upper surface 84 of substrate 82 (and the various additional materials positioned on this component as described later in this section) also includes an intermediate paint barrier layer 156 thereon which covers the conductive traces 90 (Figure 1), but is positioned between and around resistors 86 without covering them. As a result, an ink vaporization chamber 160 (FIG. 2) is formed directly above each resistor 86. Within each chamber 160, the ink materials are heated, vaporized and subsequently expelled through the holes 124 in the orifice plate 104. .

Barrier layer 156 (which is traditionally produced from conventional organic polymers, photoresist materials or similar compositions as described in US Patent No. 5,278,584) is applied to substrate 82 using conventional techniques known in the art for this purpose. goal. Specific materials that may be employed to make the paint barrier layer 156 include, but are not limited to (1) dry photoresist films containing bisphenol esters; (2) epoxy monomers; (3) melamine and acrylic monomers [e.g., those sold under the trademark "Vacrel" by E.I. DuPont of Nemours and Company of Wilmington, DE (USA)]; and (4) epoxy acrylate monomers (e.g., those sold under the trademark vParad 'by E.I. DuPont of Nemours and Company of Wilmington, DE (USA)). However, the claimed invention will not be restricted to any specific barrier compositions or methods for applying the ink barrier layer 156 in position. With reference to preferred application methods, the barrier layer 156 is provided directly by high speed centrifugal spin coating devices, spray coating units, lamination coating systems, and the like. However, the particular application method for any given situation will depend on the barrier layer 156 under consideration. In addition to clearly defining vaporization chambers 160, the barrier layer 156 also functions as a chemical and electrical insulation layer. Positioned at the top of the barrier layer, as shown in Figure 2, is an adhesive layer 164, which may: involve a number of different compositions. Representative adhesive materials for this purpose include epoxy resin and commercially available cyanoacrylate adhesives known in the art for this purpose.

Also, the adhesive layer 164 may involve the use of uncured polyisoprene photoresist compounds, as listed in U.S. Patent No. 4,245,140. 5,278,584, as well as (1) polyacrylic acid; and / or (2) a selected silane coupling agent. The term "polyacrylic acid" will be defined conventionally to encompass a compound having the following basic chemical structure [CH 2 CH (COOH) n], where n = 25 - 10,000. Polyacrylic acid is commercially available from numerous sources including, but not limited to Dow Chemical Corporation of Midland, MI (USA). Representative silane coupling agents which may be employed in connection with adhesive layer 164 include, but are not limited to, commercial products sold by Dow Chemical Corporation of Midland, MI (USA) [nos. 6011, 6020, 6030 and 6040], as well as OSI Specialties of Danbury, CT (USA) [product no. "Silquest" A-1100]. However, the above related materials are provided by way of example only and do not limit the invention in any respect.

The adhesive layer 164 is specifically used to secure / fasten the orifice plate 104 to and inside the printhead 80 so that the orifice plate 104 is fixedly fixed in position above and above substrate 82, with resistors 86 thereon. . It is important to note that the use of: a separate adhesive layer 164 may not really be necessary if the upper surface of the ink barrier layer 156 can be made adhesive in any way (for example, if it consists of a material which, when heated, becomes malleable with adhesive characteristics). However, according to the conventional structures and materials shown in Figures 1 and 2, a separate adhesive layer 164 is employed.

Also, it should be understood that there are typically a number of additional material layers positioned between the barrier layer 156, as illustrated in Figure 2 and the underlying substrate 82, which are not shown for clarity and convenience. For information on these structures, U.S. Pat. 4,535,343 to Wright et al; 4,616,408, to Lloyd; and 5,122,812 to Hess et al. may be consulted, which are incorporated herein by reference. In sum, these materials typically include the following layers (not shown): (1) a dielectric "base layer" (conventionally made of silicon dioxide [SiO2]) positioned over substrate 82, which is designed to electrically isolate the substrate 82 of resistors 86; (2) layer of a "resistive material" on the base layer that is used to create or "form" resistor elements 86 (typically made of a mixture of elemental [Al] aluminum and elemental tantalum [Ta], also known as "TaAl", which is known in the art for thin film resistor manufacturing), with other exemplary resistive materials including phosphorus-doped polycrystalline [Si} silicon, tantalum nitride [Ta2N], nichrome (NiCr), hafnium bromide [HfBr4 ], elemental niobium [Nb], elemental vanadium [V], elemental hafnium [Hf], elemental titanium [Ti], elemental zirconium [Zr], elemental yttrium [Y] and mixtures thereof; (3) a "conductive layer" of material (eg elemental aluminum [Al], elemental [Au] gold, elemental [Cu} copper and / or elemental silicon [Si], which is positioned over the resistive layer in discrete positions having gaps between them, with the "exposed" sections of the resistive layer between the gaps forming the resistor elements 86; (4) a "first passivation layer" made of, for example, silicon dioxide [SiO2], nitride silicon [SiN], aluminum oxide [Al2O3], silicon carbide [SiC], which is positioned over the conductive layer / resistor elements 86 for protective purposes; (5) an optional protective "second passivation layer" made, for example silicon carbide [SiC], silicon nitride [SiN], silicon dioxide [SiO2] or aluminum oxide [Al2O3], positioned over the first passivation layer; (6) a "cavitation layer", conductive and protective material made for example of elemental tantalum [Ta], mo elemental libdenum [Mo], elemental tungsten [W], or mixtures / alloys thereof, which is placed on the second passivation layer or first passivation layer, depending on whether the second passivation layer is employed or not; and (7) an optional inner adhesive layer disposed on the cavitation layer which may involve a number of different compositions without limitation, including conventional epoxy resin materials, standard cyanoacrylate adhesives, silane coupling agents and the like. This layer (if required as determined by routine preliminary testing) is used to secure the barrier layer 156 in position over the underlying printhead components.

According to the information provided above, it should therefore be understood that the structure shown in Figure 2 is schematic in nature and is designed to illustrate only the most basic components associated with the printhead 80. Since the present invention is directed primarily to the In the novel orifice plate of the present invention, as described in the next section, the abbreviated illustration of Figure 2 is provided for clarity and convenience, with reference being made to the above cited patent documents if additional information is desired. Referring again to the TAB bonding process, as previously discussed, the printhead 80 is finally subjected to heating and pressure within the heating / pressure application station on the TAB bonding apparatus. This step (which may otherwise be performed using other heating methods, including printhead internal heating 80) causes thermal adhesion of the internal components to each other (for example, using the adhesive layer 164 shown in the configuration of FIG. 2 and mentioned above). As a result, the printhead assembly process is completed at this stage.

The only remaining step involves cutting and separating the individual "frames" on the TAB tape (with each "frame" comprising a complete individual 80 printhead), followed by securing the printhead 80 to the housing 12 of the ink cartridge 10. Attaching the printhead 80 to the housing 12 can be accomplished in many different ways.

However, in a preferred embodiment, shown schematically in Figure 2, a portion of adhesive material 166 may be applied either to the mounting frame 56 on housing 12 and / or to selected positions on bottom surface 112 of the orifice plate. 104. The orifice plate 104 is then adhesively fixed to the housing 12 (e.g., to the mounting frame 56 associated with the extended outward printhead support structure 34 shown in Figure 1).

In accordance with the above fastening process, the substrate 82 associated with resistor assembly 96 is positioned precisely within the central cavity 50 as shown in Figure 2 so that the substrate 82 is positioned within the center of the mounting frame 56 (discussed above and shown in figure 2). In this manner, the ink flow catwalks 100, 102 (Figure 2) are formed which allow the ink materials to flow from the ink outlet port 54 into the central cavity 50 into the vaporization chambers 160 for expulsion. 10 through the holes 124 in the orifice plate 104.

To generate a printed image 170 (Fig. 1) on selected image receiving print media 172 (typically made of paper, plastic or metal) using the cartridge 10, a supply of an ink composition 174 (schematically illustrated in Figure 1) residing within the interior compartment 30 of the housing 12 passes into and through the ink outlet port 54 into the lower wall 52 of the central cavity 50. Many different materials may be used in connection with the composition. 174, including but not limited to those listed in US patent no. 5,185,034, which is incorporated herein by reference. The ink composition 174 then flows in and through the ink flow catwalks 100, 102 in the direction of the arrows 176, 180 to the substrate 82 having resistors 86 thereon. The paint composition 174 then enters the vaporization chambers 160, directly over resistors 86. Within the chambers 160, the paint composition 174 contacts resistors 86. To activate (for example, energize) resistors 86, the The printer system (not shown) containing the cartridge unit 10 causes the electrical signals to travel from the printer unit to the contact pads 120 on the upper surface 110 of the orifice plate 104. The electrical signals then pass through the pathways ( not shown) inside the plate 104 and subsequently travel along the circuit traces 114 on the bottom surface 112 of the plate 104 to resistor assembly 96 containing resistors 86. In this way, resistors 86 may be energized (e.g., heated). ) selectively to cause ink vaporization and expulsion of the printhead 80 through the nozzles 124 through the orifice plate 104. and ink 174 may then be supplied on a highly selective, on-demand basis for selected image receiving print media 172 to generate an image 170 thereon (FIG. 1).

It is important to emphasize that the printing process discussed above is applicable to a wide variety of different thermal inkjet cartridge designs.

In this regard, the inventive concepts discussed below will not be restricted to any particular printing system. However, a representative non-limiting example of a thermal inkjet cartridge of the type described above which may be used in connection with the claimed invention involves an inkjet cartridge marketed by Hewlett-Packard Company of Palo Alto. , CA (USA) under the designation "51645A". Also, further details concerning thermal inkjet processes in general are described again in the Hewlett-Packard Journal, vol. 39, no. 4 (August 1988), U.S. Patent No. 4,500,895, to Buck et al. And U.S. Patent no. No. 4,771,295 to Baker et al. (Incorporated herein by reference).

Ink cartridge 10, discussed above in connection with Figure 1, involves a "self contained" ink supply system including an "onboard" ink supply.

The claimed invention may also be used with other systems employing a printhead and an ink supply stored within an ink containment vessel, which is remotely spaced but operatively connected to and in fluid communication with the printhead. Fluid communication is typically performed using one or more tubular conduits. An example of such a system (which is known as an "off-center" apparatus) is described again in patent application pending co-titration, U.S. no. 08 / 869,446 (filed 06/06/97) entitled "AN INK CONTAINMENT SYSTEM INCLUDING A WALLED BAG FORMED OF INNER AND OUTER FILM LAYERS" (Olsen and others) and in the pending patent application, having joint owners, US at the. 08 / 873,612 (filed 06/11/97) entitled "REGULATOR FOR A FREE-INK INKJET PEN" (Hauck et al.), Both incorporated herein by reference. As illustrated in Figures 3 and 4, a representative off-center ink supply system is shown which includes a tank-type ink containment vessel 180 that is designed for remote operative connection (preferably on a gravity feed or other base). comparable) to a selected thermal inkjet printhead. Again, the terms "ink containment unit", "vessel", "housing" and "tank" should be considered equivalent in this configuration. The ink containment vessel 180 is configured in the form of an outer housing or housing 182 which includes a main body portion 184 and a panel member 186 having an inlet / outlet port 188 passing therethrough (Figures 3 and 3). 4). Although this configuration is not restricted to any particular mounting methods, in connection with housing 182, panel member 186 is optimally produced as a separate structure from main body portion 184. Panel member 186 is then attached to the main body portion 184, using known thermal welding processes or conventional adhesives (e.g., epoxy resin or cyanoacrylate compounds). However, panel member 186, in a preferred embodiment, will be considered part of the total ink containment vessel 180 / housing 182. Still with reference to figure 4, housing 182 also has an inner chamber or cavity 190 therein; for storing a supply of an ink composition 174. In addition, the housing 182 further includes an outwardly extending tubular member 192, which passes through the panel member 186 and, in a preferred embodiment, is integrally formed therewith. The term 'tubular' as used wholly in this specification will be defined to encompass a structure that includes at least one or more central walkways therethrough which are surrounded by an outer wall. The tubular member 192 incorporates the inlet / outlet port 188, as shown in Figure 4, which provides access to the inner cavity 190 within the housing 182.

The tubular member 192 positioned within the panel member 186 of housing 182 has an upper section 194 which is positioned outside the housing 182 and a lower section 196 which is positioned within the ink composition 174 in the inner cavity 190 (Figure 4 ). The upper section 194 of the tubular member 192 is operably secured by adhesive materials (e.g., conventional cyanoacrylate or epoxy compounds), friction coupling and the like to a tubular ink transfer conduit 198 positioned within port 188 shown schematically in FIG. 4. In the embodiment of FIG. 4, the ink transfer conduit 198 includes a first end 200, which is fixed, using the methods listed above, to and within the port 188 in the upper section 194 of the tubular member 192. The ink transfer line 198 further includes a second end 202, which is operable to one and remotely attached to the printhead 204, which may involve a number of different designs, configurations and systems, including those associated with printhead 80, shown in Figure 1, which should be considered equivalent to printhead 204. Also, it is important to note that Seats 80, 204 may both include the novel orifice plate structures of the present invention as described in the next section. All of these components are properly assembled within a selected printer unit at predetermined locations therein, depending on the type, size and overall configuration of the entire ink supply system. In addition, ink transfer line 198 may include at least one conventional in-line optional pump (not shown) to facilitate ink transfer.

The systems and components shown in Figures 1 to 4 are illustrative in nature. Indeed, they may include additional operating components, depending on the specific devices under consideration. The information provided above should not limit or restrict the present invention and its various configurations. Instead, the systems of Figures 1 to 4 may be varied as necessary and are presented entirely to demonstrate the applicability of the claimed invention to paint supply systems employing many different component arrangements. In this regard, any discussion of ink supply systems, specific ink containment vessels and related data will be considered representative only.

Figure 21 shows an isometric view of a typical inkjet printer 2100 that may employ the present invention. An input tray 2102 stores paper or other printable media 2104.

Referring to the schematic representation of a printing mechanism shown in Figure 22, an input means 2200 advances a single sheet of media 2104 into a printing area by use of a platen 2202, a platen motor 2204, and devices Traction (not shown). In a typical 2100 printer, one or more inkjet pens are incrementally pulled through media 2104 onto press plate 2104 by a carriage motor 2206 in a direction perpendicular to the middle inlet direction. Press plate motor 2204 and trolley motor 2206 are typically under the control of a media position and cartridge position controller 2208. An example of such positioning and control apparatus can be found in U.S. patent no. 5,070,410 entitled "Apparatus and

Method Using a Combined Read / Write Head for Processing and Storing Read Signals and for Providing Firing Signals for Thermally Actuated Ink Ejection Elements. "Therefore, medium 2104 is positioned in a location so that feathers can eject ink droplets to place dots. as required by the data entered by the printer's drop trigger controller 2210.

These ink dots are expelled from the selected holes in a printhead element of the selected feathers in a strip parallel to the sweeping direction as the feathers are driven through the middle by the 2206 trolley motor. When the feathers reach the end of their At one end of a print pass, the position controller 2208 and the press plate motor 2204 typically push the media 2104 forward. Once the feathers have reached the end of their X-direction passage over the bar, or other media carriage support mechanism, they are driven back along the media support mechanism as they continue to print, or return without printing. Media 2104 may be advanced by an incremental amount equivalent to the width of the ink eject portion of the printhead or some fraction thereof related to the nozzle spacing. The position controller 2208 determines media control 2104, pen placement (s), and selection of the correct printhead ink nozzles to create an ink image or character. Controller 2208 may be implemented in a conventional electronic hardware configuration and provided with operating instructions from conventional memory 2212. Once printing is complete, the 2100 printer ejects media 2104 into an output tray for removal by the user. Of course, the inkjet pens employing the printhead structures discussed herein substantially improve printer operation. B. New Gift Orifice Plate Structures

Invention

Having described the conventional thermal inkjet components and the printing methods associated with them, the claimed invention and its beneficial aspects will now be presented.

As indicated above, the claimed invention involves a new orifice plate structure, which is specifically designed to avoid problems associated with "puckering" as previously discussed and defined. Again, this adverse condition occurs when the orifice plate is placed in contact with a moving or stationary object. For example, the sliding passage of an ink cleaner over the orifice plate may cause this condition to occur. This contact results in a localized disruption of the orifice plate structure, with specific reference to the peripheral regions surrounding the orifices (e.g., along the outer edges thereof). As a result, the geometry of the holes in the upper surface of the plate changes. Also, "puddle" formation of paint may occur adjacent to orifice plate sections that are "raised". This "puddle" formation (which involves the accumulation of residual ink in discrete areas around the nozzles) can interfere with the ink drop expelled as it exits the orifice, thus causing ink drop path problems. These problems typically result in unwanted and uncontrolled changes in ink drop trajectory that degrade print quality. It is therefore highly desirable to avoid the conditions described above so that printhead longevity and overall print quality can be maximized over the life of the printhead.

Referring to Fig. 2, a conventional orifice plate 104 is schematically illustrated. In this figure, an elastomeric paint cleaner 210 made, for example, of rubber or plastic, is illustrated, which is of a generic type discussed, for example, in U.S. Patent no. 5,786,830. Wiper 210 is in physical, dynamic (e.g. movable) coupling with the upper surface 212 of orifice plate 104. As shown in Figure 2, however, the physical action of wiper 210 as it contacts the peripheral edges 214 of hole 124 causes a "pucker" to be created in the form of a raised section 216. The presence of this raised section 216 will result in a substantial modification of the total geometry of hole 124 in plate 104 on top surface 212 thereof. Likewise, the inner sidewall 220 associated with the hole 124 will be discontinuous and with a disruption adjacent the upper surface 212 of the orifice plate 104 (e.g., at position 222). This particular situation can again cause a number of problems including, but not limited to uncontrolled changes in the ink drop path. To avoid the difficulties described above, it has been found that the main opening (discussed below) leading into the orifice associated with the orifice plate under consideration may be "isolated" from the effects of wiper structures and the like by the formation of a "recess" (for example, an indentation or indented region) on the upper surface of the orifice plate directly above and in axial alignment with the remaining portions of the orifice. As a result, the main opening leading into the hole will be "embedded" and securely positioned below the plane over which any wipers and / or other physical objects pass during printhead operation. These aspects collectively contribute to the precise control of ink drop trajectory and the prevention of other problems associated with "wrinkling" as defined above.

Representative and preferred embodiments of the new orifice plate member associated with the invention will now be described in detail. As noted above, the present invention is not restricted to any specific building material, numerical size parameter, shape, etc., in connection with the claimed orifice plate, unless otherwise stated herein.

Referring to Figure 5, an enlarged partial cross-sectional view of a representative orifice plate 250 (also characterized as an "orifice plate member" 250) produced in accordance with the preferred embodiment of the invention is illustrated. Orifice plate 250 is made of an organic polymer (e.g. plastic) thin film composition, with the representative materials discussed above in connection with orifice plate 104 being applicable to orifice plate 250. In Figure 5, a single hole 252 is shown, with the understanding that plate 250 will optimally include a substantial number of holes therein, some or all (preferably) will have the claimed structural aspects. With reference to building materials, the organic character of plate 250 (with or without specific associated metal atoms therein), number of holes and other aspects of plate 250 (apart from the new elements described in this section [section " B "]), all of these items will be substantially the same as those discussed above in Section" A "in connection with the polymer orifice plate 104. In this regard, the technical information concerning the building materials and the other related aspects related to the orifice plate above 104 shall be incorporated by reference in connection with orifice plate 250, except as otherwise stated. As will be readily apparent from the following discussion, the main difference between the conventional orifice plate 104 and the orifice plate 250 of the present invention concerns the structural configuration of the holes 252 within the plate 250 as described below in considerable detail. .

Continuing with reference to Figure 5, the orifice plate 250 includes an upper surface 254, a lower surface 256, and a middle region 260 between the upper surface 254 and the lower surface 256. In a preferred non-limiting configuration both surfaces upper and lower 254, 256 are substantially parallel to each other as illustrated. As stated above, it is important to accurately characterize and orient the upper and lower surfaces 254, 256, relative to the other components in printhead 80 / orifice plate 250. The term "upper surface" as used and claimed herein will be defined from so as to surround the specific surface associated with the outermost orifice plate 250, and actually constitutes the "outer" surface of the orifice plate 250 / printhead 80, which is exposed to the external (outside) environment. This is the last "surface" that ink composition 174 will traverse on its journey to the selected print media (media 172). Also, it is the surface that is "cleaned" using one or more cleaning members (including the wiper 210 of FIG. 2) which are employed in conventional printing units as described, for example, in U.S. Pat. 5,786,830. In contrast, the term "bottom surface" as used in connection with orifice plate 250 is the specific surface that is positioned within (e.g., inside) the printhead 80 and is the initial surface of orifice plate 250 through from which ink composition 174 passes as it is being expelled. Bottom surface 256 is the innermost (e.g., "not exposed") surface of orifice plate 250 which is actually positioned between upper surface 254 of orifice plate 250 and substrate 82 having ejectors (s). of ink / resistor (s) 86 thereon. Finally, the bottom surface 256 is the specific surface of the orifice plate 250, which is adhered to the underlying printhead components, including the ink barrier layer 156 (Figure 2), as discussed above. Having presented these specific definitions of the upper and lower surfaces 254, 256 of orifice plate 250 which define the orientation of plate 250 relative to the remainder of printhead 80, the new aspects of the claimed orifice plate 250 will now be addressed.

In order to provide the substantial benefits described herein (including, but not limited to preventing "wrinkle" problems and maintaining proper ink drop path), the new orifice plate 250 includes at least one "recess" 262. (indentation / indentation region) beginning at the upper surface 254 of the plate and ending in a "P" position within the orifice plate 250, between the upper surface 254 and the lower surface 256 thereof (e.g., within the middle region 260, as shown in figure 5). The recess 262 includes an upper end 264 (which is positioned at and flush with the upper surface 254 of plate 250) and a lower end 266 (positioned substantially at the "Ρ" position in the middle region 260). In addition, recess 262 further includes an inner side wall 270 defining the internal boundaries of recess 262, with side wall 270 continuously extended (preferably uninterrupted), between upper end 264 and lower end 266 of recess 262. In the preferred embodiment of FIG. 5, which is designed to provide effective results, the sidewall 270 is oriented at an "X" angle of about 90Â ° (approximately a "right angle") to the upper surface 254 of the orifice plate. Also, according to this relationship and in the embodiment of Figure 5, the sidewall 270 will be substantially perpendicular to the upper surface 254 of the orifice plate 250 and vice versa as shown.

The transverse sectional configuration of recess 262 may be varied as required and desired without limitation. In particular, it may involve a number of different unrestricted configurations including, but not limited to those which are square, triangular, oval in shape, circular (preferred as illustrated in Figure 6), or any other regular or irregular shape. The remainder of this discussion (including the following description of additional configurations) will involve a circular recess 262 with the understanding that other configurations are possible. Although it is preferred that recess 262 has a uniform cross-sectional shape (e.g., circular, square, etc.) along its entire length from upper end 264 to lower end 266, a change may also occur. one or more times at any position along the length / extension of recess 262, if desired. The upper end 264 of the recess 262 on the upper surface 254 of the orifice plate 250 has a first hole or opening 272 thereto. The first aperture 272 (with specific reference to the peripheral edges 274 thereof) is optimally flush with the upper surface 254 of the orifice plate 250. Again, the present invention should not be restricted to any specific shape or configuration. in connection with the first opening 272, which may be circular (preferred as shown in figure 6), square, oval, triangular or any other regular or irregular shape. The function of the first aperture 272 will be discussed in more detail below.

As illustrated in figures 5 and 6, the lower end 266 of the recess 262 in the orifice plate 250 further comprises (in a preferred non-limiting configuration) a lower wall 276 which is optimally planar in configuration. In the representative embodiment of Fig. 5, the bottom wall 276 is preferably oriented at an "X" angle of about 90Â ° (approximately a right angle) to the side wall 270 and is therefore substantially perpendicular thereto. In this configuration, the bottom wall 276 will be substantially parallel to the top surface 254 (and the bottom wall 256) of the orifice plate 250, as shown. Also, in the preferred non-limiting embodiment of Figure 5, the bottom wall 276 is substantially the same size / area as the first aperture 272, so that the peripheral edges 274 of the first aperture 272 are directly above the outer edge portions 280 of the bottom wall 276 as shown in Figure 5. Despite the right angle (approximately 90 °) relationship between (1) the bottom wall 276 and side wall 270; and (2) the sidewall 270 and the upper surface 254 of the claimed orifice plate 250 are again preferred, it should be understood that this geometric relationship may be varied as follows according to a number of alternative embodiments.

In the orifice plate 250 illustrated in figures 5 and 6, recess 262 will be substantially cylindrical or disc-shaped which again is designed to produce highly effective results in the present invention. The extent "L" associated with recess 262 in the configuration of figures 5 and 6 (which may also be characterized as the depth of recess 262, if desired) may be varied without limitation as determined according to routine preliminary pilot testing. , involving numerous considerations, including the type of printing system in which the 80 printhead will be employed and other extrinsic factors. However, in a preferred non-limiting configuration, the "L" extension of recess 262 will be around 1 to 3 / μm (which, again, is subject to change if necessary). In the system of Figure 5, the extension "I: 'will actually involve the distance between the point" Ρ "as referenced above and the upper surface 254 of the orifice plate 250. Incidentally, it should be noted that the total thickness" T " The orifice plate 250 will, in a preferred embodiment, be applied for all embodiments of the claimed invention described herein, from about 25 to 504m, although other values may be employed if desired.

Positioned at the lower end 266 of the recess 262, within the orifice plate 250 is a second hole or aperture 282 having peripheral edges 284. In the preferred embodiment of figures 5 and 6, the second aperture 282 runs through the lower wall 276 and is disposed of. optimally at its center as illustrated (although the second aperture 282 may be placed in any non-centered position within the lower wall 276 if necessary). In the preferred orientation of FIGS. 5 and 6, the center point "C" of the first aperture 272 is in axial alignment (e.g. directly above) the center point "C1" of the second aperture 282. Likewise, the second aperture 282 is level, optimally with the lower wall 276 at the lower end 266 of recess 262 as illustrated. The present invention will not be restricted to any specific shape or configuration in connection with the second aperture 282, which may be circular (preferable as illustrated in Figure 6), square, oval, triangular or any other regular or irregular shape. Although better results are obtained, if the cross-sectional shape of the first aperture 272 and the second aperture 282 are the same (e.g. circular as in the configuration of figures 5 and 6), both apertures 272, 282 may have different shapes. relative to each other if necessary and desired according to the preliminary routine test.

As previously discussed, the second aperture 282 functions primarily as the "main aperture" associated with orifice 252 through which the ink composition 174 passes on its way to print medium 172 (FIG. 1). It is an important aspect of the present invention, which is common to all related configurations, that the second aperture 282 (e.g. "the main aperture") is positioned below the upper surface 254 of orifice plate 250 to Avoid being in contact with the ink cleaning members (eg wiper 210) or other objects that may pass along the upper surface 254 of the orifice plate 250. According to the "protected" position occupied by the second opening 282 as described herein, it cannot be disfigured, or otherwise "puckered" by passing the above objects along the upper surface 254 of the plate 250. At this point, additional information with respect to the relationship between the first aperture and the second aperture 282 is secured. Basically, first aperture 272 and second aperture 282 are separated from each other by a distance, which is defined by the extension "L" as previously discussed. In addition, a new aspect of the claimed invention that is likewise generally applied to all configurations described in this section is the size ratio of first aperture 272 relative to second aperture 282. Basically, first aperture 272 is larger in size. than the second aperture 282, with the second aperture 282 being again "recessed" according to the design described above. The term "larger in size" as used in connection with first and second apertures 272, 282 basically involves a situation where the transverse sectional area of first aperture 272 exceeds the transverse sectional area of second aperture 282 with term "area" being defined conventionally, depending on the shape of the aperture under consideration. For example, in situations involving openings 272, 282, square or rectangular, the transverse sectional area will involve the length of aperture 272 and / or aperture 282 multiplied by its width. In an orifice plate 250 including first and second circular apertures 272, 282, its transverse sectional area will be defined conventionally to encompass the formula "7ir2", where r = the radius of aperture 272 and / or aperture 282. Also, in situations involving openings 272, 282 having other shapes (triangular, oval, etc.) the "conventional" formulas that are normally used to calculate the area of these shapes would be employed.

When first and second circular apertures 22,282 are employed, as shown, for example, in Figures 5 and 6 (which are preferred for numerous reasons, including ease of production, absence of angled surfaces and the like), the term "larger in size" may also be defined with respect to the comparative diameter of each aperture 272,282. With reference to the preferred embodiment of FIG. 5, first aperture 272 and second aperture 282 are both completely circular in cross section, as shown in FIG. noted above, with first aperture 271 having a first diameter "D" and second aperture 282 having a second diameter "D". It should be understood that all of the figures in the drawings and the length / diameter dimensions shown herein are not necessarily drawn to exact scale and therefore may be varied as required. In this particular non-limiting configuration, the first diameter "D" of first aperture 272 will preferably be at least about 40 μm, or longer (e.g. longer / larger) than the second diameter "Di" of a second aperture 282. A proportionally comparable value will also apply for situations in which the relative sizes of the first and second apertures 272, 282 are based on the transverse sectional area as previously discussed. In addition, in a representative, non-limiting configuration, the first diameter "D" associated with first aperture 272 will be about 50 to 80 μm, with the second diameter "Di" from second aperture 282 being about 10 to 40 μm. However, as previously indicated, the claimed invention will not be restricted to this numerical range or any other numerical parameters, except as otherwise stated herein. Therefore, such values should be considered representative and not limiting.

By using a first aperture 272, which is larger than the second aperture 282, in all of the various configurations described in this section, the transmission of physical forces from the upper surface 254 / first aperture 272 of orifice plate 250 to the lower wall 276 Second aperture 282 within recess 262 is minimized due to structural and size differential relationships between these components. Although the exact physical mechanisms by which these benefits occur are not fully understood, they are nevertheless important and provide excellent results. In particular, the size ratio discussed above, in which first aperture 272 is larger in size than second aperture 282, effectively facilitates proper ink drop trajectory. Any deformities associated with the peripheral edges 274 of the first aperture 272 (Figure 5) on the upper surface 254 of the orifice plate 250, caused by cleaning or other physical abrasion processes (eg "puckering"), will not adversely affect the drop trajectory. ink leaving the second aperture 282. Specifically, the trajectory of the ink drop will not be affected given the larger size of the first aperture 272 relative to (1) the second aperture 282; and (2) the ink drop through the first opening 272, with the size of the ink drop being defined basically by the size of the second opening 282. The ink drop will be sufficiently small according to its initial passage through the second opening 282, to avoid substantial contact with enlarged first aperture 272 (and associated peripheral edges 274). Any "frowns" on the peripheral edges 274 of the first aperture 272 will therefore not present ink path problems in view of the "embedded" nature of the second aperture 282.

Other important features associated with recess 262 in this (functionally) embodiment of the invention include the orientation of the sidewall 270 at an "X" angle about 90Â ° (approximately a right angle) to the upper surface. 254 of orifice plate 250. This design provides a high degree of structural integrity / stiffness and enables the physical forces applied to the upper surface 254 of orifice plate 250 to be effectively confined to this region without substantial transmission into recess 262, bottom wall 276 and second opening 282. The use of bottom wall 276 and its orientation at an angle "XI" about 90 ° (approximately a right angle) to side wall 270 also provides additional reinforcement of the bottom plate 276. 250 so that the structural integrity of the second aperture 282 is maintained even when the upper surface 254 of the orifice plate 250 is subjected to to physical force.

Continuing to refer to Figure 5, another important component of orifice 252 in orifice plate 250 involves an elongated ink transfer hole 286. The ink transfer hole 286 is positioned under recess 262 and is in fluid communication with it. Ink transfer hole 286 is in partial or complete (preferably) axial alignment with recess 262 and vice versa, as previously discussed. This relationship is illustrated in FIG. 5, with the longitudinal central geometry "A 'of recess 262 being in substantially complete alignment and in line with the longitudinal central geometry" A "of hole 286. As a result of this preferred structural relationship, the materials (ink composition 174) that are expelled by the ink ejector (s) / resistor (s) 86 will initially go up, enter hole 286, pass through recess 262, and exit hole plate 250 / printhead 80 to provide the desired media 172.

To accomplish this and from a functional point of view, the ink transfer hole 286 begins again at the lower end 266 of the recess 262 (e.g., the second opening 282 therein). The second aperture 282 of recess 262 actually comprises the upper end 290 of hole 286 with both components at this point (e.g., position "" "in figure 5). The upper end 290 of hole 286 comprises a third aperture 292 which is in fact the same as and equivalent to second aperture 282 in recess 262. Thus, all information, size parameters and the like associated with second aperture 282 , are equally applicable and incorporated by reference with respect to third aperture 292 (which is not separately discernible / visually separable from second aperture 282). Hole 286 also includes a middle section 294 continuing downwardly through orifice plate 250 as illustrated and finally terminating at bottom surface 256 of plate 250. As shown in Figure 5, hole 286 terminates at a lower end 296 including a fourth aperture 297, which is substantially flush with the lower surface 256 of the orifice plate 250. The fourth aperture 297 is the lowest aperture on all orifice 252 / orifice plate 250 and is the first portion of orifice 252 to receive the thermally excited ink composition 174 during the ink expulsion process. The claimed invention will not be limited in connection with the size and shape of the fourth aperture 287, which may be varied as required and desired according to routine preliminary pilot testing. For example, the transverse sectional configuration of the fourth aperture 297 may be circular (preferred), square, oval, triangular, or any other regular or irregular shape depending on many factors including the intended use of printhead 80. In a preferred embodiment, in which the fourth aperture 297 has a completely circular shape, will have a representative non-limiting diameter "D2" around 20 to 80 μm, with the understanding that this range is provided for purposes of example only.

Again, orifice plate 250, in all embodiments presented herein, will not be restricted to any specific numerical dimension, diameter or area values. However, in a non-limiting representative configuration involving first, second, third and fourth openings 272, 282, 292, 297, circular, the following example ratios will provide excellent results: (1) Di = 10 to 40 μm (2) D = D, + 40 μm and (3) D2 = 2 (D1).

Although a number of different structural designs may be employed in connection with paint transfer hole 286, hole 286 optimally has a uniform cross-sectional shape throughout its length. However, hole 286 may be configured such that it changes its transverse sectional shape one or more times at any position (s) along its length. Representative cross-sectional configurations associated with hole 286 include, but are not limited to circular (preferred), square, oval, triangular, or any other regular or irregular shape. As illustrated in Figure 5, the ink transfer hole 286 further includes a continuous interior side wall 299, which establishes the boundaries of hole 286 within the middle region 260 of orifice plate 250. In a preferred embodiment, side wall 299 will be oriented to form an acute angle "X 2" relative to the upper surface 254 of the orifice plate 250, with the term "acute angle" being defined again to encompass an angle of less than 90Â ° (about 25Â °). at 75 ° being preferred in a non-limiting manner). However, in an alternative embodiment which should not limit the invention in any way, the angle "X" may actually be 90 ° or greater if necessary and desired. Therefore, in a non-restrictive, representative configuration, a wide angular range around 25 to 145 ° (or even greater than 145 °) may be employed in connection with angle "X2". The use of an acute angle "X2" in connection with the sidewall 299 of the ink transfer hole 286 is preferred for a number of reasons including ease of fabrication using mass production fabrication techniques, which involve ablation to laser and the like. The angular orientation forms a hole 286 which is substantially cone-shaped (more specifically a truncated or frustoconical cone configuration) having an enlarged fourth aperture 297 having a larger size compared to the third aperture 292. The term "larger in size" ", as used in connection with the third and fourth apertures 292, 297, will be defined in an equivalent manner relative to the relationship between the first and second apertures 272, 282. According to this design, paint materials (e.g., paint composition 174) readily enters hole 286 during the ink expulsion process (with specific reference to the enlarged fourth aperture 297 facilitating this process). However, the selection of any given internal design with respect to the claimed ink transfer hole 286 and the recess 262 on the upper surface 254 of the orifice plate 250 can be determined again using the routine preliminary pilot test. , taking into consideration the factors listed above, including the end use associated with the printhead 80, the chosen building materials, etc. With reference to the full length of the ink transfer hole 286, the invention will not be restricted to any specific values. In a representative configuration designed to provide optimum functional capabilities, bore 286 will have an "L2." Span of around 24 to 47 μm, which is again subject to change as necessary.

Having described the preferred embodiment of figures 5 and 6, it is important to emphasize that all the angular and dimensional relationships listed above will not restrict the invention in any way and instead constitute exemplary values which are presented as preferred versions of the invention. Many other variations are possible within the scope of the invention as long as the claimed orifice plate 250 having recess 262 and bore 286 offers the desired functional capabilities discussed above. For example, as shown in Figure 7, an inner sidewall 299, associated with the ink transfer hole 286, is provided wherein (1) the angle "X2" is about 90 ° (approximately a right angle ); and (2) the sidewall 270 / bottom wall 276 (with particular reference to its outer edge portions 280) have been "smoothed" to form a bottom wall retaining recess 262, which is substantially "cupped". It should be noted that either or both of the items listed above may be incorporated into the configuration of FIG. 5 (or any other configuration herein, if necessary and desired). Indeed, all variations / modifications described in this section (Section "B") can be incorporated into the orifice plate 250 in various combinations and permutations without restriction. Some additional alternatives will now be discussed, which are equally encompassed by the present invention as claimed, with the understanding that the invention will not be restricted to the following alternatives only. Referring to Figure 8, another alternative embodiment of the invention is schematically illustrated. All information, materials, numerical parameters, functional characteristics, operational aspects and other aspects of the configurations of figures 5 and 7 are equally applied to the configuration of figure 8 (except for the specific modifications provided below). 5 through 7 is therefore incorporated by reference with respect to orifice plate 250 of FIGURE 8. Meanwhile, orifice plate 250 illustrated in the configuration of FIGURE 8 has been modified with reference to the angular relationship between (1) sidewall 270 recess-associated 262; and (2) the upper surface 254 of orifice plate 250. Specifically, the angle "X" in the configuration of Figure 8 has been expanded to exceed 90 °, thereby forming an "obtuse" angle. An obtuse angle is again defined generally to encompass an angle that is greater than 90 °. Although the present invention is not restricted to any specific obtuse angles, in this case it is preferable that the I'V angle associated with this configuration be around 100 to 145 ° so as to produce the orifice plate 250 shown in FIG. Figure 8. This structure again provides a number of important benefits, including the "isolation" of the second aperture 282 within recess 262, in accordance with the "embedded" nature of the second aperture 282. Also, when considering both embodiments illustrated in FIGS. 5 and 8, it can be stated in general that the extensive representative range associated with angle "X" is about 90 to 145Â ° (which includes the right angle ratio of figure 5 and the ratio of preferred obtuse angle of figure 8).

With further reference to the alternative embodiment of FIG. 8, the first aperture 272 will be even larger than the first aperture 272 shown in FIGS. 5 and 6 and described above. The extent to which the first aperture 272 is increased according to the configuration of FIG. 8 will vary depending on the obtuse angle "X" that is selected for the use of orifice plate 250. The total size of the first aperture 272 (well as its format, as discussed previously) will not be limited as long as the first aperture 272 is in fact larger in size (defined above) than the second aperture 282. However, it is anticipated that the implementation of the configuration of figure 8 , according to the general information provided above, will result in a typical non-limiting increase in the size of the first aperture 272 (for example, the transverse sectional area and / or diameter) by about 10 to 50% compared to the size of the first aperture. first aperture 272 in the configuration of figures 5 and 6. However, this range is representative only and should not limit the invention in any way. The total length / depth of the recess 262 in the configuration of figure 8 may be adjusted as required or desired, preferably within the "L" value range listed above in connection with the system of figures 5 and 6, or larger if required. . The desired parameters associated with all variables in this configuration (with specific reference to "L", "X" and "X1") will be determined according to the preliminary preliminary pilot test, taking into account a number of items. including the other components that are employed to manufacture printhead 80, as well as the manner in which printhead 80 will be used.

Finally, in the present embodiment shown in Figure 8, the angle "Χ1", which defines the relationship between (1) the bottom wall 276; and (2) the sidewall 270 will also become "obtuse" as previously defined, ie exceeding 90 °. Although the claimed invention is not restricted to any values determined in connection with angle "X1", this angle will generally be equivalent to the value associated with angle "X", (assuming that the bottom wall 276 is substantially parallel to the top surface). 254 of orifice plate 250 as shown in Figure 8 (which is not necessarily required but preferred) For example, if angle "X" is 120 °, then angle "X1" will also be 120 ° again assuming a substantially parallel relationship is maintained between the lower wall 276 and the upper surface 254 of the orifice plate 250. However, it should be emphasized again that the configuration of figure 8 (and the numerical values listed above) are representative only and should not limit the invention in any respect With reference to the configuration of the ink transfer hole 286, this portion of the orifice 252 may have the relative aspects above in connection with the configurations of figures 5 to 7, with the data associated therewith being incorporated by reference, with respect to the system of figure 8.

Figure 9 illustrates yet another embodiment of the invention. All information, materials, numerical parameters, functional characteristics, operational aspects and other aspects of the configurations of figures 5 to 8 apply equally to the configuration of figure 8 (except for the specific modifications provided below). The specific information associated with the configurations of figures 5 to 8 is therefore incorporated by reference with respect to the system of figure 9. With reference to the configuration of figure 9 it differs from the system of figures 5 and 6 with respect to the angular relationship between (1) the bottom wall 276 within recess 262; and (2) the sidewall 270 in recess 262.

Specifically, the angle "X1" between both of these components has an obtuse feature as previously defined, ie greater than 90 °. At the same time, the angle "X" with respect to the sidewall 270 and the upper surface 254 of the orifice plate 250 remains around 90 (approximately a right angle) according to the system of figures 5 and 6. Although this specific configuration is not restricted to any given "X1" obtuse angle (with a number of variations being possible), a representative and preferred range associated with the "X1" angle in the configuration of Figure 9 will be about 100 to 145. °. Even though the angle "X" is optimally around 90 ° (approximately a right angle), as previously noted, it should be emphasized that the angle "X" may also be larger than this value, with the obtuse angle values expressed above, in connection with the configuration of figure 8, being equally applicable and incorporated by reference with respect to the system of figure 9, if desired. Further, in the orifice plate 250 of FIG. 9, the lower wall 276 is no longer parallel with the upper surface 254 of orifice plate 250.

The total length / depth of the recess 262 in the configuration of figure 9 (as measured from the upper surface 254 of the orifice plate 250 to the second aperture 282) may be adjusted as required or desired, preferably within the "L" value range. , listed above in connection with the system of figures 5 and 6, or larger if required. The desired parameters, associated with all variables in the present invention (with specific reference to "L", "X" and "X1"), will be determined according to the preliminary preliminary pilot test, taking into account a number of items, including the other components that are employed to manufacture the printhead 80, as well as the manner in which the printhead 80 will be used. Still with reference to figure 9, the first and second openings 272, 282 in this version of the claimed orifice plate 250 will optimally and most often remain the same from a standpoint regarding the initial configuration of the figures. 5 and 6, although the size values associated with these elements can be modified as needed. Referring to the configuration of the ink transfer hole 286 in FIG. 9, this portion of orifice 252 may have the aspects listed above in connection with the configurations of FIGS. 5 to 8, with the associated data being incorporated by reference in FIG. Finally, the orifice plate 250 of FIG. 9 again provides a number of important benefits, including "isolation" and securing the second aperture 282 within recess 262 according to the "embedded" nature. "from the second opening 282.

Referring to Figure 10, a further alternative embodiment of the invention is schematically illustrated. All information, materials, numerical parameters, functional characteristics, operational aspects and other aspects of the configurations of figures 5 to 9 are equally applicable to the configuration of figure 10 (except for the specific modifications listed below). Specific information associated with the configurations of FIGS. 5 to 9 is therefore incorporated by reference with respect to orifice plate 250 of FIGURE 10. Meanwhile, orifice plate 250, illustrated in the configuration of FIGURE 10, has also been modified with reference to FIG. reference to the angular relationship between (1) the sidewall 270 associated with the recess 262; and (2) the upper surface 254 of the orifice plate 250. Specifically, the angle "X" in the configuration of Figure 10 has been expanded to exceed 90 ° thereby forming an "obtuse" angle as defined above. Although the present invention is not restricted to any specific obtuse angles, in this case, it is preferred that the angle "X" associated with this configuration (figure 10) be around 100 to 145 °, in order to produce the structure of the figure. Also, the orifice plate 250 shown in Figure 10 has been further modified with reference to the angular relationship between (1) the bottom wall 276 in recess 262; and (2) recess 262 sidewall 270. Specifically, the angle "X1" associated with this configuration has been expanded to exceed 90Â °, thereby also forming an "obtuse" angle as previously defined. Although the present invention is not restricted to any specific obtuse angles, in this case, it is preferred that the angle "X1" associated with this configuration (figure 10) is about 120 to 165 ° to make the orifice plate Also, the angle "X1" associated with the structure of figure 10 should be sufficient to render the lower wall 276 unparalleled and sloped downwardly from the upper surface 254 of orifice plate 250. This design again provides a number of important benefits, including the "isolation" and protection of the second aperture 282 within recess 262 according to the "embedded" nature of the second aperture 282. Continuing with reference to the alternative embodiment of figure 10, the first aperture 272 will be larger than the first opening 272 shown in figures 5 and 6 and described above. The extent to which the first aperture 272 is enlarged in the system of FIG. 10 will vary depending on the obtuse angle "X" that is selected for use in orifice plate 250. The total size of the first aperture 272 (as well as its shape as shown in FIG. discussed previously) should not be limited as long as the first aperture 272 is actually larger in size (defined above) than the second aperture 282. However, it is anticipated that the implementation of the configuration of FIG. The general information provided above will result in a typical non-limiting increase in first aperture size 272 (e.g., cross-sectional area and / or diameter) by about 10 to 50%, compared to first aperture size 272, in the configuration of the first aperture 272. Figures 5 and 6. However, this range is representative only and should not limit the invention in any way. The total length / depth of recess 262 in orifice plate 250 of FIG. 10 (as measured from upper surface 254 of plate 250 to second aperture 282) may be adjusted as required or desired, preferably within the "L" value range. "listed above in connection with the system of figures 5 and 6, or larger if required. The desired parameters associated with all variables in the present configuration (with specific reference to "L", "X" and "X1") will be re-determined according to the preliminary preliminary pilot test, taking into account a number of items. , including the other components that are employed to manufacture the printhead 80, as well as the manner in which the printhead 80 will be used. It should be emphasized again that the configuration of figure 10 (and the numerical values listed above) are representative only and should not limit the invention in any respect. Referring to the configuration of the ink transfer hole 286 in FIG. 10, this portion of orifice 252 may have the aspects listed above in connection with the configurations of FIGS. 5 to 9, with the associated data being incorporated as a system reference. of figure 10.

Still another non-limiting configuration of the claimed invention is illustrated in FIG. 11. Again, all information, materials, numerical parameters, functional characteristics, operational aspects and other aspects of the configurations of FIGS. 5-10 are equally applicable to the configuration of FIG. 11 (except for the specific modifications provided below). The specific information associated with the configurations of figures 5 to 10 is therefore incorporated as a reference to the system of figure 11.

With reference to orifice plate 250 of FIG. 11, it differs from the system of FIGS. 5 to 6 in a number of ways. First, orifice plate 250, illustrated in Figure 11, has been modified with reference to the angular relationship between (1) the sidewall 270 associated with recess 262; and (2) the upper surface 254 of the orifice plate 250. Specifically, the angle "X" in the configuration of Figure 11 has been expanded to exceed 90 °, thereby forming an "obtuse" angle. An obtuse angle is generally defined again to encompass an angle that is greater than 90 °. In particular, the angle "X" employed in a preferred version of the configuration of figure 11 will involve the same characteristics as that of the angle "X" used in the configuration of figure 8, with the above related information in connection with the system of figure 8 being incorporated by reference with reference to orifice plate 250 of FIG. 11. Although the present invention is not restricted to any specific obtuse angles, in this case it is preferred that the angle "X" associated with this configuration be about 100 to 145 ° (substantially the same as in figure 8) to produce the orifice plate 250 shown in figure 11. However, as noted above, other values are also applicable in connection with angle "X". For example, if desired, the angle "X" could be around 90Â ° (approximately a right angle) or smaller ("sharp"), provided that the first aperture 272 is larger in size (defined above) than the second opening 282.

The system of figure 11 also differs from that of figures 6 and otherwise which will be discussed now. This difference involves the angular relationship between (1) the bottom wall 276 of recess 262; and (2) the sidewall 270 in recess 262. Specifically, the angle "X1" between both of these components in the specific configuration of Figure 11 will be of sufficient value to produce an upwardly extended "crown" structure 300 of which ink materials (including ink composition 174) will be expelled during operation of printhead 80. In particular, the angle "Xi" should be sufficient to cause bottom wall 276 in recess 262 to be tilted upward, as illustrated (to at least some degree) with respect to the lower surface 256 of the orifice plate 250 so that the crown structure 300 can be produced. Although this particular version of the invention is not restricted to the determined "Xi" angle (with a number of variations being possible), effective results are obtained if the "XI" angle is acute (less than 90 °) with a representative range. It is preferred to associate the angle "X1" in the configuration of Figure 11 being around 45 to 80. However, it should be understood that the angle "X1" can actually be 90, or greater if necessary, provided a structure is produced. wherein the lower wall 276 is inclined upwardly to at least some degree from the lower surface 256 of the orifice plate 250 as previously observed. As a result, the bottom wall 276 is not parallel to the bottom wall 256 of the orifice plate 250 and forms an upwardly inclined angle with respect to the bottom surface 256 to generate the crown structure 300.

The total length / depth of recess 262 in orifice plate 250 of FIG. 11 (as measured from upper surface 254 of plate 250 to second aperture 282) may be adjusted as desired, preferably within a "L" value range. listed in connection with the system of figures 5 and 6, or larger if required. The desired parameters associated with all variables in the present configuration (with specific reference to "L", "X" and "Xi") will again be determined according to the preliminary routine pilot test, taking into account a number of items including the other components that will be employed to manufacture the printhead 80, as well as the manner in which the printhead 80 will be used. Referring further to Figure 11, the first and second apertures 272, 282 in this version of the claimed orifice plate 250 will optimally remain substantially equal in size from the initial configuration of Figures 5 and 6. , although the values associated with these elements can be modified as needed. Referring to the configuration of the ink transfer hole 286 in FIG. 11, this portion of orifice 252 may have the aspects listed above in connection with the configurations of FIGS. 5 to 10, with the associated data being incorporated by reference to the FIG. Finally, the orifice plate 250 of Figure 11. Finally, the orifice plate 250 of Figure 11 again provides a number of important benefits including "isolation" and securing the second aperture 282 within the recess. 262 according to the "embedded" nature of the second aperture 282. In addition, the crown structure 300, discussed above, further provides additional integrity in the orifice plate 250. Notwithstanding the information and parameters listed above in connection with all the various designs shown in figures 5 to 11, these multiple configurations do not limit the invention in any way and instead represent the versions different from the invention which may provide the desired benefits. Additional variations are possible and encompassed within the invention as defined by the claims set forth below.

C. Ink Supply Systems Using the New Printheads / Nozzle Cards and Manufacturing Methods Associated With These

According to the information provided above, a unique orifice plate 250 and printhead 80 associated with the latter, having a high degree of durability, longevity and resistance to the effects of physical engagement with ink cleaners and other structures, are provided. . These benefits are achieved according to the specialized orifice plate 250 having the unique orifice design described above with the plate 250 being constructed of organic polymer. It is a highly desirable and novel aspect of the present invention that all of the above benefits can be achieved by using a thin-film polymeric orifice plate 250 of the type discussed herein. Additional benefits associated with this orifice plate 250 are summarized in the previous sections. In addition to the components, aspects and novel elements of the orifice plate 250 described herein (including the specialized recess 262 employed in connection with the orifices 252 of the plate 250), this invention also encompasses (1) an "ink supply system" which is constructed using the claimed printhead 80 having the orifice plate 250 attached thereto; and (2) a new method for manufacturing printhead 80 which employs the specialized components listed in Sections "A" and "B" above. Accordingly, all data in Sections "A" and "B" are to be incorporated entirely by reference in the present invention (Section "C").

In order to produce the ink supply system of the invention, an ink containment vessel is provided which is operatively connected to and in fluid communication with the claimed printhead 80 comprising the new orifice plate 250 discussed above. (including any of the foregoing configurations as shown in figures 5 to 11 and others encompassed by the claimed invention). The term "ink containment vessel" as defined above may encompass any type of housing, tank or other structure designed to maintain an ink supply within (including ink composition 174). The terms "ink containment vessel", "housing", "chamber" and "tank" are to be considered functionally and structurally equivalent. The ink containment vessel may encompass, for example, the housing 12 used in the self-contained cartridge 10 of FIG. 1, or the housing 172 associated with the "off-center" system of FIGS. 3 and 4. Also, the expression "operatively connected" "covers a situation where the claimed printhead 80 (having the new orifice plate 250 attached thereto) is either directly attached to an ink containment vessel as shown in Figure 1 or remotely connected to a containment vessel in an "off-center" manner as illustrated in figures 3 and 4. Again, an example of an "onboard" system of the type shown in figure 1 is provided in US patent no. No. 4,771,295, by Baker et al., With "off-center" ink supply units being described in patent application pending co-holders, U.S. 08 / 869,446 (filed 06/06/97) entitled "AN INK CΟΝΤΑINMENT SYSTEM INCLUDING PLURAL-WALLED BAG FORMED OF INNER AND OUTER FILM LAYERS" (Olsen and others) and the pending patent application pending U.S. no. 08 / 873.612 (filed 06/11/97 entitled "REGULATOR FOR A FREE-INK INKJET PEN" (Hauck and others), with all of these items being incorporated herein by reference. These documents describe and support an "operative connection" of the claimed printhead (for example, printhead 80 or 2004) to a suitable ink containment vessel, with the data and benefits listed in Sections "A" and "Β", again being incorporated by reference in the current section ( This data includes representative building materials, parameters and the claimed new aspects associated with orifice plate 250, orifice 252, and printheads 80, 204. In this regard, the ink supply systems of the present invention will include in a preferred setting

(1) an ink containment vessel which may involve a number of different types as previously discussed;

(2) a printhead comprising a substrate, at least one ink ejector on the substrate (with many different ink nozzles being suitable for use including, but not limited to one or more resistor elements); and (3) a new orifice plate member positioned over and above the substrate. The orifice plate will have the characteristics and aspects described in all embodiments presented herein (see Figures 5 to 11) and any other embodiments encompassed by the claimed invention, as previously noted. The resulting ink supply system provides all previously related benefits including, but not limited to, durability and maintaining the proper ink drop path over the life of the printhead. With reference to the claimed method for producing the new printhead 80 of the present invention, a specialized orifice plate member (i.e., orifice plate 250) is provided, which includes the structures, components and aspects listed above and shown. In this regard, all information presented in Sections "A" and "Β" with reference to the new orifice plate 250 is again applied to the claimed method and is incorporated in this section (Section "C") as reference. A substrate 82 having at least one ink ejector thereon (preferably a resistor 86) is also provided. Components, which may be employed in connection with substrate 82 and ink ejector, should likewise be of the generic types discussed above in Sections "A" and "B". It should also be noted that the claimed methods, devices and systems are not restricted solely to the representative components described in Sections "A" and "B" and are not limited to the structural configurations of the new orifice plate 250, which are shown in Figures 5 to 5. Instead, the present invention encompasses any and all modifications, variations, and equivalents which are suitably encompassed by the following related claims.

Once substrate 82 and ink ejector have been provided, the new orifice plate member 250 (having specialized recess 262) is fixedly secured in position over and above substrate 82 to produce the printhead. 80 complete. Representative methods for fixing these components together are listed in Section "A" above. Suitable techniques for accomplishing these purposes include the use of various adhesives to secure orifice plate 250 in position (against the underlying paint barrier layer 156) or by self-adhering orifice plate 250 as previously indicated. With reference to the adhesive materials, Section "A" discusses the ink barrier layer 6 (shown in Figure 2), along with placing an adhesive layer 164 thereon to adhere the barrier layer 156 to the paint plate. overlapping hole 250. The adhesive layer 164 may involve a number of different compositions as previously discussed. Representative adhesive materials suitable for this purpose include commercially available epoxy resin and cyanoacrylate compounds known in the art. Also, the adhesive layer 164 may involve the use of uncured polyisoprene photoresist compounds as described in U.S. patent no. 5,278,584, as well as (1) polyacrylic acid; and / or (2) a selected silane coupling agent. The term "polyacrylic acid" is conventionally defined to encompass a compound having the following basic chemical structure [CH 2 CH (COOH) n], wherein n = 25 - 10,000. Polyacrylic acid is commercially available from numerous sources including, but not limited to Dow Chemical Corporation of Midland, MI (USA). Representative silane coupling agents which are suitable for use herein include, but are not limited to, commercial products sold by Dow Chemical Corporation of Midland, MI (USA) [nos. 6011, 6020, 6030 and 6040, as well as by OSI Specialties of Danbury, CT (USA) [product no. "Silquest" A-1100]. However, the materials listed above are again provided by way of example only and should not limit the invention in any way.

The adhesive layer 164 is specifically used to secure / secure the orifice plate 250 (or any other orifice plates covered by the claimed invention) to and within the printhead 80 so as to be fixedly secured in position over and above substrate 82. having the ink nozzles (resistors 86) thereon. It is important to note again that the use of a separate adhesive layer 164 may not really be necessary if the top of the barrier layer 156 can be made adhesive in any way (eg if it consists of a material which, when heated, becomes malleable with adhesive characteristics). Accordingly, the present invention should not be restricted to any specific methods, techniques or materials for mounting the printhead 80, with particular reference to fixing the orifice plate 250 to the underlying printhead components 80. Finally, some information Further provision is made with reference to the formation of the orifice 252 described above including the new recess 262 (all configurations) and the ink transfer hole 286 therein. Many different methods known in the art for forming apertures in plastics / polymers and the like can be employed for this purpose without limitation including, but not limited to, laser ablation techniques, chemical etching methods and the use of conventional mechanical drilling instruments. /drilling. Such instruments would be specifically circumvented or otherwise configured to produce the desired designs associated with recess 262 and ink transfer hole 286 in each of the claimed holes 252. With reference to the use of laser ablation techniques, the methods described in U.S. Pat. 5,305,015 and 5,278,574 are to be considered applicable and incorporated herein by reference. Specifically, a mask structure, initially created using lithographic techniques, is employed for this purpose. A conventionally designed laser system is then selected which, in a preferred embodiment, involves an "excimer laser" of a type selected from the following alternatives F2, ArF, KrCl, KrF or XeCl. Using this specific system (with preferred pulse energies greater than about 100 millijoules / cm2 and pulse durations less than about 1 microsecond, the holes 252 and the associated structures (for example, the recesses of the 286) can be formed with a high degree of accuracy, precision and control.However, the claimed invention is not limited to any particular manufacturing method, with other methods also being suitable for producing orifice plate 250 / nozzles. 252 complete, including conventional ultraviolet removal processes (for example using ultraviolet light in the 150 to 400 nm range) as well as standard chemical etching, embossing, reactive ion etching, ion beam milling and known processes Non-Concentric Reaming of a Hole

As described in detail above, there are many known design and processed-induced aspects that affect the location of the tail detachment. These aspects include whether or not the resistor (not shown) and hole 252 are lagged, the shape of hole 286, the topology of hole 252, the smoothing and uniformity of the exit edge of hole 286, and other associated defects, such as puddles. , localized scratches and purses. All of these aspects introduce a relatively uncontrolled variation to the resulting tail detachment location and drop direction.

However, by using a non-concentric drawdown in the hole, the location of the tail detachment can be controlled. As illustrated in Figures 12 and 13, this embodiment of the present invention takes advantage of the natural topography produced as a result of the shallow exit side ablation process performed to create a shallow lowering 400. When a shallow exit side ablation process is realized on the upper surface 254 of an orifice plate 250, a unique profile is created. The lower wall profile 276 of the lowering 400 is hemispherical around the center of the lowering 400. A portion of the lower wall 276 is substantially flat 402 and a portion is slightly inclined 404. As a result, a groove 406 is formed between the side wall 270 and the inclined portion 404 of the bottom wall 276.

In Fig. 13 the undercut 400 is non-concentric with the hole 286, whereas in Fig. 12 the undercut is concentric with the hole. By offsetting the lowering 400 from hole 286, the hemispherical profile of the lowering modifies the continuous hole sidewall 299 so that a portion of the sidewall 408 is lower than the opposite portion 410. Stated another way, the idea is to locate the hole outlet 252 and the undercut 400 so that the hole outlet is centered away from the center of the undercut (i.e. decentralized) and one side of the hole is positioned at a height higher than than the other on the geometry axis of interest, which is usually the sweeping geometry axis. This height differential results in a consistent detachment of the tail to the highest portion 410 of the sidewall. Consequently, this consistent detachment provides improved sweep geometry axis steering control. Preferably, this configuration may be constructed by ablation of the exit side of the desired drawdown design on the outlet side of the flexible wire in a two-step ablation process using a suitably designed mask. The ablated top detail shape is not critical and could be a non-concentric circle, or any other symmetrical or asymmetrical shape around the outlet. In addition, essentially any size of groove 406 could be used. However, the depth of the drawdown 400 should preferably be optimized so as not to be too deep to retain the ink meniscus. In short, this non-concentric configuration provides a new way to control the location of the tail detachment and improves the direction of expelled ink without affecting any of the design parameters of the trigger chamber. All prior art ways of affecting the tail detachment site affect the design of the firing chamber and, therefore, the drop ejection characteristics. In addition, this configuration of the present invention may be combined with a camera design optimized for other design variables, but which has poorly induced tail detachment targeting in the scanning benefits.

Deep Reaming of a Hole

As discussed above, overrun of the meniscus or puddle formation induced by tail detachment may result in the degradation of the direction of the thermal inkjet feathers. This degradation varies depending on the size and shape of the ink pool on a hole surface. Consequently, ink targeting is highly variable.

The deep reaming configuration of the present invention provides a design that contains and limits puddle formation. In addition, this setting also minimizes and / or eliminates overrun of the meniscus. Therefore, this setting prevents degradation of the steering.

In particular, steering degradation is prevented by the use of deep symmetrical or asymmetrical lowering. Such deep symmetrical drawdown 414 is shown in Figure 14 and a deep asymmetric drawdown 416 is shown in Figure 15. Of course, these deep drawdowns 414, 416 could have any shape including, but not limited to circular, triangular, square, pentagonal, etc. as well as any irregular shape. In addition, deep undercuts 414, 416 could be either concentric (as shown in figures 14 and 15) or non-concentric (as shown in figure 13) with bore 286.

The undercuts 414, 416 are preferably deep enough to retain the ink meniscus 418 and to act as a fluid conduit to connect any ink pools back to the ink transfer hole 286. Therefore, this configuration avoids and / or minimizes the extent of any puddle that is formed. This, in turn, helps reduce the induced puddle degradation associated with thermal inkjet printing.

This embodiment of the present invention is preferably constructed by performing the outlet side ablation of the desired undercut design on the upper surface 254 of the orifice plate structure 250. Again, any upper side ablation design could be used as long as the undercuts 414, 416 are deep enough to hold the ink meniscus 418 and to act as a fluid conduit for the ink pools.

In short, this deep recess configuration provides a new way to control puddle length and reduce associated steering degradation without affecting any of the trigger chamber design parameters. All previously known means of puddle control or reduction affect ink or the chamber design and thus adversely affect the drop ejection characteristics and print quality of the thermal inkjet pen. In addition, this configuration of the present invention may be combined with a camera design optimized for other design variables, but which have unsatisfactory targeting due to the formation of large and variable puddles. Examples of this include, but are not limited to, high aspect ratio asymmetrical holes that have a one-sided tail detachment and a large amount of high frequency puddle formation.

Therefore, for example, this setting can be used to achieve improved high frequency routing combined with the design benefits of asymmetrical non-circular holes.

F. Partial Reaming of a Hole

As discussed above, prior art thermal inkjet feathers suffer from trajectory and direction variations as they print. One reason for this has been the historical use of circular holes. Because the holes were circular, there was no specific reason why the tail of an inkjet drop favored one position or another on the periphery of the hole to make its final exit. Again, this leads to the possibility of tail detachment varying from one side of the hole to the other due to events occurring within the firing chamber or in the upper side puddles on the orifice plate structure. Of course, this variation of tail detachment can lead directly to stitch placement errors. In order to overcome this problem, this embodiment of the present invention adds at least some asymmetry to the hole. By adding this asymmetry, this configuration forces the tail to go in the same direction each time.

In particular, this configuration modifies a lowering design such that a portion 400 of the upper side surface 254 of the orifice plate structure 250 is not removed. In other words, instead of etching a circular counterbore on the upper side surface 254, only a partial (i.e. asymmetrical) lowering is created on the upper side surface 254.

This partial lowering 422 is shown in Figures 16 and 17. The partial lowering 422 may be created by, for example, the use of laser ablation and a suitably formed mask.

By removing the unmasked portion of the upper side surface 254, the configuration provides an unremoved portion 420 of the orifice plate structure 250 extending from the recess wall 424 to the portion 420 directly into the bore 286 itself. Therefore, This portion 420 acts as a modifier for the ink meniscus at the point where it intersects the hole outlet.

In particular, portion 420 draws the drop tail to the droplets of ink expelled at this intersection. Accordingly, the portion 420 attracts the ink tail to the ink droplets expelled at this intersection. Consequently, this setting forces the tail to go in the same direction each time and thus eliminates variations of the prior art tail detachment.

G. Ablation of Exit Side of Exit Edge of Hole in Hole

As noted above, thermal inkjet printers typically employ one or more wiper elements that keep the outer surface of the orifice plate clean and free of residual ink, as well as other foreign matter, such as paper fibers. And the cleaning process often adversely affects printheads that employ multiple orifice plates. In particular, the passage of the wiper element (s) over the orifice plates often causes physical deformations (e.g., puckering) at the orifice plate edges. The resulting changes in hole geometry / planarity cause significant changes in the ink drop path. These undesirable changes in orifice plate geometry prevent the ink droplet from flowing in its intended direction. Instead, the droplet is improperly expelled and is delivered to an unwanted position on the print media material (e.g., paper and / or other substrates).

Deformation of the orifice plate as described above (including the creation of extraneous wrinkle structures around the peripheral edges of the orifices) may also cause the accumulation or formation of ink "puddles" in these regions. As discussed above, this may further alter the ink drop trajectory by causing undesired interaction between the ink drop being expelled, particularly the terminal portion of each drop or its "tail" with accumulated ink adjacent the holes. As a result, print quality degradation occurs over time.

A perspective view of a typical prior art hole is shown in Figure 18. As illustrated in the figure, the laser-removed hole exit edges 426 are sharp and not uniform as produced. In particular, laser hole removal is similar to drilling a hole in a piece of metal. The inlet side of the bore edge is relatively smooth, while the bore outlet edge is sharp and has burrs. This is the same phenomenon that occurs with laser ablation and the resulting sharp, nonuniform hole exit edges 426.

This embodiment of the present invention provides a solution to this "frown" problem. In particular, this configuration eliminates the problem of puckering by providing a hole 286 with a smooth and uniform exit edge. Prior to this invention, there were no known solutions for producing a smooth and uniform bore exit edge. More particularly, this configuration provides straightening of the exit edge by performing a removal process on the upper side of a pre-existing hole. In other words, after hole 286 is created, an ablation process is performed on the upper side of the hole. This straightening of the exit edge is preferably accomplished by reaming the hole 286. The undercut can be either a shallow undercut 428 as shown in Fig. 19 or a deep undercut 430 as depicted in Fig. 20. In either case Reaming an existing hole 286 generates smooth and uniform hole exit edges 432.

Although shallow and deep recesses 428, 430 are represented as being circular and concentric, any shape and alignment for the ablation mask may be used. For example, undercuts 428, 430 could be symmetrical or asymmetrical and could be concentric or non-concentric with respect to bore 286. In addition, any continuous channel width or groove could be provided around the nozzle column. In addition, if desired, the entire upper side surface 254 of the orifice plate structure could be removed rather than simply reaming an area around each hole 286.

Therefore, this embodiment of the present invention solves the problems of the prior art without adding a new material or new interface in order to eliminate the generation of frills. This is particularly important since new materials and interfaces are difficult and expensive to test and approve for manufacturing. In addition, new materials and interfaces can lead to reliability issues in the presence of aggressive paint chemicals.

H. Conclusion

In conclusion, the present invention involves a novel printhead and specialized orifice plate structure which are characterized by many benefits. These benefits again include (1) a substantial increase in printhead / orifice plate longevity; (2) the ability to maintain precise control over the ink drop trajectory; (3) claimed orifice plate compatibility with print units employing a variety of different wiper systems that are used to clean the printhead; (4) the prevention of premature orifice plate damage despite its thin film plastic / polymeric characteristic; (5) the ability to provide a high durability thin film polymeric orifice plate structure that can maintain its light and thin profile while avoiding the problems discussed above; and (6) accomplishing these objectives using a technique that avoids the deposition of additional material layers and / or chemical compositions on the orifice plate.

The present invention has been described herein with reference to its specific exemplary embodiments. It will be apparent to those skilled in the art that a person, by understanding this invention, may design changes, or other configurations or variations, that utilize the principles of this invention, without losing the spirit and scope of the invention as set forth in the appended claims. For example, the invention is not to be limited to any specific ink supply systems, operating parameters, numerical values, dimensions, ink compositions and component orientations within the above duct lines, except as otherwise stated herein. All are considered to be included within the scope, spirit and scope of the invention. The report and the drawings should therefore be considered in an illustrative and non-restrictive sense. Accordingly, it is not intended to limit the invention except as necessary in view of the appended claims.

Claims (7)

A component for use in a printing system, comprising: a substrate (82) including at least one fluid ejector; and an orifice member (250) positioned over said substrate, said orifice member having at least one fluid transfer hole (286) extending therethrough, said orifice member further including: an upper surface (254) ) defining an upper opening for the fluid transfer bore; a lower surface (256) defining a lower aperture for the fluid transfer bore; and an oval recess (400) on the upper surface, the recess being non-concentric with the fluid transfer bore, said component being characterized in that the recess further defines a groove (406) near and around the perimeter of the aperture. higher. Component according to claim 1, characterized in that the fluid transfer bore has at least one side wall (299), and at least a portion (410) of said side wall is higher than at least the other portion (408) of said sidewall. Component according to Claim 1, characterized in that each of the shapes: the cross-section of the undercut (400), the upper opening of the fluid transfer bore and the lower opening of the fluid transfer bore Circular. Component according to Claim 1, characterized in that the undercut (400) has an upper oval edge and a lower oval edge, with a perimeter of the upper oval edge being greater than a perimeter of the lower oval edge. . Component according to Claim 1, characterized in that the undercut (400) is of sufficient depth to retain the fluid meniscus (418) in said undercut. Component according to Claim 1, characterized in that the undercut (400) has a lower surface forming a groove (406) around the perimeter of the upper aperture, with lower surface walls sloping away from the hole. transfer fluid (286). Component according to Claim 1, characterized in that the oval lowering is a partial lowering (422) defining an oval lowering portion of the upper surface (254) and a remaining portion of the upper surface, the oval lowering portion. being in fluid communication and not being concentric with the fluid transfer bore, the remaining portion attracting fluid as it is supplied from the component, the partial undercut (422) including at least one recess (262) in said member hole (250) starting at said upper surface (254) thereof and ending at a position within said hole member between said upper surface (254) and said lower surface (256), said recess having a depth about 1 µm and comprising an upper end, a lower end and a side wall (270) therebetween, said upper end comprises said first opening and said lower end comprising a lower wall (276), said lower wall comprising a second opening (282) therethrough, said first opening being larger than said second opening, said lower wall being oriented at an obtuse angle of approximately 100 ° to said sidewall of said recess, wherein the at least one fluid transfer hole is in fluid communication with said recess, said hole starting at said lower end of said recess and terminating at said lower surface of said orifice member.